JP3550065B2 - Gasoline sulfur reduction in fluidized bed catalytic cracking - Google Patents

Description

【００５１】
実施例２
触媒シリーズ２の調製
Ｖ／ＵＳＹ触媒（触媒Ｆ）は、シリカ／アルミナ比５．４及び２．４３５ｎｍのユニット・セル・サイズを有するＵＳＹゼオライトを用いて調製した。シリカゾル／クレイマトリックス中に５０重量％のＵＳＹ結晶を含有する水性スラリーを噴霧乾燥することによって流動触媒を調製した。マトリックスは、２２重量％のシリカゾル及び２８重量％のカオリンクレイを含有していた。噴霧乾燥した触媒を硫酸アンモニウムの溶液を用いて交換することによりＮＨ_４ ^＋と交換し、その後乾燥させた。ＵＳＹ触媒を、バナジウムオキサレートの溶液に含浸させることによって目標の０．５重量％のＶとした。
【００５２】
ＲＥ＋Ｖ／ＵＳＹ触媒（触媒Ｇ）は、シリカ／アルミナ比５．５及び２．４５４ｎｍのユニット・セル・サイズを有するＵＳＹゼオライトを用いて調製した。ＵＳＹは、硫酸アンモニウムの溶液を用いて交換することによりＮＨ_４ ^＋と交換した。ＮＨ_４ ^＋交換を行ったＵＳＹは、その後、希土類元素塩化物の混合物溶液と交換することによって、希土類カチオン（例えば、Ｌａ^３＋、Ｃｅ^３＋など）と交換した。使用した希土類元素溶液は、そのＣｅ^３＋の大部分が抽出されて、従ってごく少量のＣｅを含有していた。ＲＥ交換したＵＳＹは、更に洗浄し、乾燥し、回転式焼成装置の中でスチームの存在下、７６０℃（１４４０゜Ｆ）にて焼成した。スチーム焼成によって、ゼオライトのユニット・セル・サイズは２４．４０Åへ低下し、バナジウムの存在によって安定性は向上した。シリカゾル／クレイマトリックス中に５０重量％のＲＥ−ＵＳＹ結晶を含有する水性スラリーを噴霧乾燥することによって流動触媒を調製した。マトリックスは、２２重量％のシリカゾル及び２８重量％のカオリンクレイを含有していた。噴霧乾燥した触媒を硫酸アンモニウムの溶液を用いて交換することによりＮＨ_４ ^＋と交換し、その後乾燥させ、５４０℃（１０００゜Ｆ）にて２時間焼成した。焼成を続けて、ＲＥ／ＵＳＹ触媒にＶＯＳＯ_４溶液を含浸させた。
【００５３】
触媒Ｈは、ＵＳＹの交換に、主としてＣｅＣｌ_３を含有する混合ＲＥＣｌ_３の溶液を用いたこと以外は、触媒Ｇの場合と同様の手順を用いて調製した。触媒Ｈは、シリカ／アルミナ比５．５及び２．４５４ｎｍのユニット・セル・サイズを有する市販のＵＳＹゼオライトを用いて調製した。ＵＳＹは、硫酸アンモニウムの溶液を用いて交換することによりＮＨ_４ ^＋と交換した。ＮＨ_４ ^＋交換を行ったＵＳＹは、その後、ランタンを含有するＣｅＣｌ_３により交換した。交換したＵＳＹは、更に洗浄し、乾燥し、回転式焼成装置の中でスチームの存在下、７６０℃（１４４０゜Ｆ）にて焼成した。スチーム焼成によって、ゼオライトのユニット・セル・サイズは２．４４０ｎｍへ低下した。シリカゾル／クレイマトリックス中に５０重量％の希土類元素含有ＵＳＹ結晶を含有する水性スラリーを噴霧乾燥することによって流動触媒を調製した。マトリックスは、２２重量％のシリカゾル及び２８重量％のカオリンクレイを含有していた。噴霧乾燥した触媒を硫酸アンモニウムの溶液を用いて交換することによりＮＨ_４ ^＋と交換し、その後乾燥させ、５４０℃（１０００゜Ｆ）にて２時間焼成した。焼成を続けて、触媒にＶＯＳＯ_４溶液を含浸させた。焼成した触媒の物理的特性を表２にまとめて示す。
【００５４】
【表２】

【００５５】
実施例３
触媒シリーズ３の調製
Ｖ／ＵＳＹ触媒（触媒Ｉ）は、シリカ／アルミナ比５．４及び２．４３５ｎｍのユニット・セル・サイズを有するＨ型−ＵＳＹゼオライト（結晶）を用いて調製した。４０重量％のＵＳＹ結晶、２５重量％のシリカ、５重量％のアルミナ、及び３０重量％のカオリンクレイを含有する水性スラリーを噴霧乾燥することによって流動触媒を調製した。噴霧乾燥した触媒は、５４０℃（１０００゜Ｆ）にて３時間焼成した。得られたＨ型−ＵＳＹ触媒を初期湿潤含浸法（ｉｎｃｉｐｉｅｎｔ ｗｅｔｎｅｓｓ ｉｍｐｒｅｇｎａｔｉｏｎ）によってバナジウムオキサレートの溶液に含浸させることにより目標の０．４重量％のＶとした。含浸させたＶ／ＵＳＹ触媒は更に５４０℃（１０００゜Ｆ）にて３時間空気焼成した。最終的な触媒は０．３９％のＶを含有する。
【００５６】
Ｃｅ＋Ｖ／ＵＳＹ触媒（触媒Ｊ）は、触媒Ｉと同じ噴霧乾燥したＨ型−ＵＳＹ触媒中間体から調製した。Ｈ型−ＵＳＹ触媒は、初期湿潤含浸法を用いてＣｅ（ＮＯ_３）_３溶液に含浸させることにより目標の１．５重量％のＣｅ添加とした。得られたＣｅ／ＵＳＹ触媒は、５４０℃（１０００゜Ｆ）にて３時間空気焼成した後、５４０℃（１０００゜Ｆ）にて３時間スチーム処理した。その後、触媒は、初期湿潤含浸法により、バナジウムオキサレート溶液に含浸させることによって目標の０．４重量％のＶとした。含浸させたＣｅ＋Ｖ／ＵＳＹ触媒は、更に５４０℃（１０００゜Ｆ）にて３時間空気焼成した。最終的な触媒は、１．４％のＣｅ及び０．４３％のＶを含有する。
【００５７】
【表３】

【００５８】
実施例４
触媒シリーズ４の調製
５０％のＵＳＹ、２１％のシリカゾル及び２９％のクレイからなる、単一のソースの材料を噴霧乾燥したものから、触媒シリーズ４のすべての試料を調製した。出発物質のＵＳＹは、５．４のシリカ／アルミナ比及び２．４５４ｎｍのユニット・セル・サイズを有していた。噴霧乾燥した触媒は、ｐＨ６のＮＨ_４ＯＨ及び（ＮＨ_４）_２ＳＯ_４の溶液を用いてスラリー化してＮａ^＋を除去した後、水洗し、６５０℃（１２００゜Ｆ）にて２時間焼成した。
【００５９】
Ｖ／ＵＳＹ触媒（触媒Ｋ）は、上記のＨ型−ＵＳＹ触媒を用いて調製した。Ｈ型−ＵＳＹ触媒は、初期湿潤含浸法を用いてバナジウムオキサレート溶液に含浸させることにより目標の０．５重量％のＶとした。含浸させたＶ／ＵＳＹ触媒は、更に６５０℃（１２００゜Ｆ）にて２時間空気焼成した。最終的な触媒は、０．５％のＶを含有する。
【００６０】
Ｃｅ＋Ｖ／ＵＳＹ（触媒Ｌ）は、上記のＨ型−ＵＳＹ触媒を用いて調製した。Ｈ型−ＵＳＹ触媒は、ＣｅＣｌ_３の溶液を用いて交換させることにより目標の０．７５重量％のＣｅ添加とした。得られるＣｅ／ＵＳＹ触媒は、空気焼成し、初期湿潤含浸法を用いてバナジウムオキサレート溶液を含浸させることにより目標の０．５重量％のＶとした。含浸させたＣｅ＋Ｖ／ＵＳＹ触媒は更に空気焼成した。最終的な触媒は、０．７２％のＣｅ及び０．５２％のＶを含有する。
Ｃｅ＋Ｖ／ＵＳＹ（触媒ｍ）は、上記のＨ型−ＵＳＹ触媒からＣｅＣｌ_３の溶液を用いて交換させることにより目標の３重量％のＣｅ添加とした。得られるＣｅ／ＵＳＹ触媒は、空気焼成し、初期湿潤含浸法を用いて０．５重量％のＶを目標としてバナジウムオキサレート溶液を含浸させた。含浸させたＣｅ＋Ｖ／ＵＳＹ触媒は更に空気焼成した。最終的な触媒は、１．５％のＣｅ及び０．５３％のＶを含有する。
【００６１】
Ｃｅ＋Ｖ／ＵＳＹ（触媒Ｎ）は、上記のＨ型−ＵＳＹ触媒から初期湿潤含浸法によってＣｅＣｌ_３の溶液に含浸させることにより目標の１．５重量％のＣｅ添加とした。得られるＣｅ／ＵＳＹ触媒は、空気焼成し、初期湿潤含浸法を用いて０．５重量％のＶを目標としてバナジウムオキサレート溶液を含浸させた。含浸させたＣｅ＋Ｖ／ＵＳＹ触媒は更に空気焼成した。最終的な触媒は、１．５％のＣｅ及び０．５３％のＶを含有する。
【００６２】
これらの触媒は、その後スチーム処理して失活させ、流動床スチーム処理装置内で、５０％のスチーム及び５０％のガスを使用して７７０℃（１４２０゜Ｆ）にて２０時間、ＦＣＣ装置内での触媒失活をシミュレートした。ガスストリームは、空気から、Ｎ_２、プロピレン，及びＮ_２混合物、並びにＮ_２へ１０分ごとに変化させ、空気に循環して戻してＦＣＣ装置（繰り返しスチーム処理）のコーキング／再生サイクルをシミュレートした。２組の失活触媒の試料の再生を行った。１つのバッチの触媒については、スチーム失活サイクルを空気燃焼（酸化的−終了）により終了し、もう１つのバッチの触媒についてはプロピレン（還元的−終了）により終了した。「還元的−終了」のコークス含量は、０．０５％のＣ以下である。焼成及びスチーム処理（酸化的−終了）触媒の物理的特性を表４にまとめて示している。
【００６３】
【表４】

【００６４】
実施例５
触媒シリーズ５の調製
４０％のＵＳＹ、３０％のコロイダルシリカゾル及び３０％のクレイからなる、単一のソースの材料を噴霧乾燥したものから、触媒シリーズ５のすべての試料を調製した。出発物質のＨ型−ＵＳＹは、５．４のバルク・シリカ／アルミナ比及び２．４３５ｎｍのユニット・セル・サイズを有していた。噴霧乾燥した触媒は、５４０℃（１０００゜Ｆ）にて３時間空気焼成した。
Ｃｅ／ＵＳＹ触媒（触媒Ｏ）は、上記のＨ型−ＵＳＹ触媒を用いて調製した。Ｈ型−ＵＳＹ触媒は、１．５重量％のＣｅ添加を目標として、初期湿潤含浸法を用いてＣｅ（ＮＯ_３）_３溶液に含浸させた。得られたＣｅ／ＵＳＹは、５４０℃（１０００゜Ｆ）にて空気焼成した後、５４０℃（１０００゜Ｆ）にて３時間スチーム処理した。
【００６５】
Ｃｅ＋Ｖ／ＵＳＹ触媒（触媒Ｐ）は、触媒Ｏから調製した。Ｃｅ／ＵＳＹ触媒を初期湿潤含浸法によりバナジウムオキサレート溶液に含浸させることによって、目標の０．５重量％のＶとした。含浸させたＣｅ＋Ｖ／ＵＳＹ触媒は、乾燥し、５４０（１０００゜Ｆ）にて空気焼成した。最終的な触媒は、１．４％のＣｅ及び０．４９％のＶを含有する。
Ｃｅ＋Ｖ／ＵＳＹ触媒（触媒Ｑ）は、触媒Ｏから、０．５重量％のＶ添加を目標として、〜３のｐＨにてＶＯＳＯ_４の溶液に含浸させることによって調製した。得られるＣｅ／ＵＳＹ触媒は、乾燥し、５４０（１０００゜Ｆ）にて３時間空気焼成した。焼成した触媒の物理的特性を表５にまとめて示す。
【００６６】
【表５】

【００６７】
実施例６
ＲＥ＋Ｖ／ＵＳＹ／シリカゾル触媒の調製
ＲＥ＋Ｖ／ＵＳＹ触媒（触媒Ｒ）は、シリカ／アルミナ比５．５及び２．４６５ｎｍのユニット・セル・サイズを有するＮａＹゼオライトを用いて調製した。ゼオライトＹは、硫酸アンモニウムの溶液を用いて交換することによってＮＨ_４ ^＋により交換した。ＮＨ_４ ^＋交換したゼオライトＹは、その後、希土類元素塩化物の混合物溶液を用いて交換することによって、希土類カチオン（例えば、Ｌａ３＋、Ｃｅ３＋など）と交換し、その希土類元素塩化物の混合物溶液からは大部分のＣｅ^３＋が抽出されており、従って、溶液はきわめて少量のセリウムを含有していた。ＲＥ交換したＹは、更に水洗し、乾燥させ、スチームの存在下で７０５℃（１３００゜Ｆ）にて２時間焼成した。スチーム焼成によってゼオライトのユニット・セル・サイズは減少し、バナジウムの存在によって安定性は向上した。シリカゾル／クレイマトリックス中に５０重量％のＲＥ−ＵＳＹ結晶を含有する水性スラリーを噴霧乾燥することによって流動触媒を調製した。マトリックスは、２２重量％のシリカゾル及び２８重量％のカオリンクレイを含有していた。噴霧乾燥した触媒は、硫酸アンモニウムの溶液を用いて交換することによってＮＨ_４ ^＋により交換した。焼成を続けて、ＲＥ／ＵＳＹ触媒にバナジウムオキサレート溶液を含浸させた。焼成した触媒の物理的特性を表６にまとめて示す。
【００６８】
【表６】

【００６９】
実施例７
Ｃｅ＋Ｖ／ＵＳＹ／シリカゾル触媒の調製
Ｃｅ＋Ｖ／ＵＳＹ触媒（触媒Ｓ）は、シリカ／アルミナ比５．５及び２．４５４ｎｍのユニット・セル・サイズを有するＮａＵＳＹゼオライトを用いて調製した。ＵＳＹは、硫酸アンモニウムの溶液を用いて交換することによりＮＨ_４ ^＋と交換した。ＮＨ_４ ^＋交換を行ったＵＳＹは、その後、塩化セリウム及び少量のセリウム以外の希土類元素イオン（例えば、Ｌａ^３＋、Ｐｒ、Ｎｄ、Ｇｄなど）を含有する溶液と交換することによって、Ｃｅ^３＋と交換した。Ｃｅ交換したＵＳＹは、更に洗浄し、乾燥し、スチームの存在下、７０５℃（１３００゜Ｆ）にて２時間焼成した。スチーム焼成によって、ゼオライトのユニット・セル・サイズは低下し、バナジウムの存在によって安定性は向上した。シリカゾル／クレイマトリックス中に５０重量％のＣｅ／ＵＳＹ結晶を含有する水性スラリーを噴霧乾燥することによって流動触媒を調製した。マトリックスは、２２重量％のシリカゾル及び２８重量％のカオリンクレイを含有していた。噴霧乾燥した触媒を硫酸アンモニウムの溶液を用いて交換することによりＮＨ_４ ^＋と交換し、その後乾燥させ、５４０℃（１０００゜Ｆ）にて１時間焼成した。焼成を続けて、Ｃｅ／ＵＳＹ触媒にバナジウムスルフェート溶液を含浸させた。焼成した触媒の物理的特性を表７にまとめて示す。
【００７０】
【表７】

【００７１】
実験手順：分解性能の評価
実施例１〜７の触媒のＦＣＣについての評価を行い、その結果を実施例８〜１５において報告する。減圧軽油（ＶＧＯ）フィードを用いて、ＡＳＴＭ Ｄ−３９０７の手順を改良したＡＳＴＭマイクロアクティビティテスト（ＭＡＴ）により、軽油の分解活性及び選択性について配合触媒（試料＋平衡触媒）を試験した。添加触媒のいくつかのものについては、減圧軽油及び水素処理したフィードを用いて、順環式ライザー・パイロット装置において評価を行った。３種のＶＧＯフィード及びこれらの実施例において用いた１種の苛酷に触媒フィード水素処理を行ったフィード（ＣＦＨＴ）の組成を表８に示す。
【００７２】
【表８】

【００７３】
分解転化率の範囲は、５２７℃（９８０゜Ｆ）での反応のランにより、触媒／油比を変化させることによって得られた。分解した生成物についてのカットポイントは、以下のとおりであった：
ガソリン Ｃ_５＋〜２２０℃（１２５゜Ｆ〜４３０゜Ｆ）、
軽質ＬＣＯ ２２０℃〜３１０℃（４３０゜Ｆ〜５９０゜Ｆ）、
重質ＬＣＯ ３１０℃〜３７０℃（５９０゜Ｆ〜７００゜Ｆ）、
軽質燃料油（ＬＦＯ） ２２０℃〜３７０℃（４３０゜Ｆ〜７００゜Ｆ）、
重質燃料油（ＨＦＯ） ３７０℃＋（７００゜Ｆ＋）。
各物質収支からのガソリン範囲生成物は、ガソリンの硫黄濃度を測定するために、硫黄ＧＣ（ガスクロマトグラフィー）（ＡＥＤ）を用いて分析した。ガソリンの蒸留カットポイントの変動に伴なう硫黄濃度においての実験誤差を減らすために、合成原油（ｓｙｎｃｒｕｄｅ）中のチオフェンからＣ_４−チオフェンまでの範囲にわたる硫黄種（ベンゾチオフェンおよびより沸点の高いＳ種を除く）を定量し、合計を「分留ガソリン（ｃｕｔ−ｇａｓｏｌｉｎｅ）のＳ」と定義した。
ガソリン範囲より高い沸点範囲の留出物フラクションの硫黄含量を測定するため（実施例１４及び１５）、合成原油を常圧蒸留に付してガソリンを分離した。それから塔底フラクションを更に減圧蒸留に付して２種のＬＦＯ／ＬＣＯフラクション（軽質ＬＣＯフラクション及び重質ＬＣＯフラクション）ならＨＦＯフラクションを生成させた。ＬＣＯ試料中の硫黄種は、Ｊ＆Ｗ １００ｍＤＢ−石油カラム及びＳｉｅｖｅｒｓ ３６５５Ｂ 硫黄デテクターを備えたガスクロマトグラフ装置を用いて定量した。各ＬＣＯ硫黄種の濃度は、ＸＰＳ法によって測定した全硫黄含量及びＧＣからの硫黄種の割合に基づいて計算した。
【００７４】
シリーズ１触媒の流動床式接触分解の評価
実施例１からの触媒を、流動床スチーマーにおいて、上記実施例４で説明したように、５０％スチーム及び５０％ガスを用いて、７７０℃（１４２０゜Ｆ）にて２０時間スチーム失活させ、空気燃焼（酸化的−終了）によって終了した。スチーム処理された添加物触媒２５重量％を、ＦＣＣ装置からの非常に低い金属レベル（１２０ｐｐｍのＶ及び６０ｐｐｍのＮｉ）を有する平衡触媒に配合した。マイクロアクティビティテストにおいて、分解フィードとしてＶＧＯＮｏ．１を使用して、触媒の接触分解性能を評価した。触媒の性能を表９にまとめて示すが、生成物の選択率は、一定の転化率、２２０℃（４３０゜Ｆ）又はそれ以下の物質へのフィードの転化率へ補間した。
【００７５】
【表９】

【００７６】
表９の触媒／油比には、失活Ｖ／ＵＳＹ及びＥ触媒を配合したものは、６５％転化率を達成するために、１００％平衡触媒の基本ケースの場合と比べて、より高い触媒／油比（３．３対３．０の触媒／油比、即ち、活性の１０％低下）を必要とするということが示されている。このことは、平衡触媒と対比して、Ｖ／ＵＳＹ触媒の分解活性がより低いことに基づくものである。対照的に、ＲＥ＋Ｖ／ＵＳＹ触媒を添加しても、６５％転化率を達成するために触媒／油比を増大することはない。これらの触媒／油比の結果は、ＲＥ＋Ｖ／ＵＳＹ触媒が、Ｖ／ＵＳＹ触媒よりもより良好な分解活性を保持し、及びより良好な安定性を有するということを示している。
【００７７】
平衡触媒の基本のケースと比較して、Ｖ／ＵＳＹ触媒及びＲＥ＋Ｖ／ＵＳＹ触媒を添加することによって、全生成物収率構造について多少の変化がもたらされている。水素及びコークスの収率がわずかながら増加している。Ｃ_４−ガス、ガソリン、軽質燃料油比及び重質燃料油の収率についても多少の変化が観察されている。Ｖ／ＵＳＹ触媒及びＲＥ＋Ｖ／ＵＳＹ触媒を添加することによって、ガソリンＳ濃度は実質的に変化している。平衡ＦＣＣ触媒に、触媒Ａ又はＢ（Ｖ／ＵＳＹ対照触媒）をそれぞれ２５重量％配合した場合、それぞれ３９．０％及び４０．８％のガソリン硫黄濃度の低下が達成された。平衡触媒に２５重量％のＲＥ＋Ｖ／ＵＳＹ触媒（触媒Ｃ及びＤ）を添加した場合には、ガソリン硫黄濃度の低下は対照触媒（３８〜４０％）に匹敵する。希土類金属の大部分としてＣｅを含有するＲＥ＋Ｖ／ＵＳＹ触媒（触媒Ｅ）は、ガソリンのＳについて４３．１％の低下をもたらして、ガソリンＳ含量を更に４％低下させている、即ち、Ｖ／ＵＳＹ触媒及び混合ＲＥ＋Ｖ／ＵＳＹ触媒よりも１０％もの向上を達成している。全ての触媒のバナジウム添加（０．３６〜０．３９％）は同等であった。
【００７８】
これらの結果は、希土類元素を添加することによってＶ／ＵＳＹ触媒の分解活性が向上するということを示している。分解生成物の収率における変化は軽微である。希土類元素イオンの中で、セリウムは、Ｃｅ＋Ｖ／ＵＳＹ触媒が、流動床式接触分解条件において、より高い分解活性を示すだけでなく、向上したガソリン硫黄低減活性を示すという特有の特性を示している。大量のセリウムレベルを伴なわない希土類元素ＲＥ／ＵＳＹ触媒は、ガソリンＳ低減についてＶ／ＵＳＹ触媒と比べてあまり利点はもたらさないが、その一方で、セリウムはＶ／ＵＳＹ触媒又はＲＥ＋Ｖ／ＵＳＹ触媒（高いセリウムレベルを有さないもの）のガソリン硫黄レベルを更に低下させる。
【００７９】
シリーズ２触媒の分解活性の評価
実施例２からの触媒（シリーズ２の触媒、触媒Ｆ、Ｇ、Ｈ）を、種々の時間で７７０℃（１４２０゜Ｆ）にてスチーム処理させて、触媒の安定性を比較した。触媒は、５０％スチーム及び５０％ガスを用いて（上記実施例４で説明したような繰り返しスチーム処理、還元的−終了）を用いて、２．３時間、５．３時間、１０時間、２０時間及び３０時間で流動触媒スチーマーにおいてスチーム処理した。失活させた触媒の表面積の保持を図２にプロットして示す。
【００８０】
スチーム失活させた触媒の、軽油の分解活性についての試験を、減圧軽油（ＶＧＯ）Ｎｏ．２（硫黄分２．６重量％以上）を用いて、ＡＳＴＭマイクロアクティビティテスト（ＡＳＴＭ手順 Ｄ−３９０７）により行った。３０秒の接触時間及び５４５℃（９８０゜Ｆ）の反応温度にて、２２０℃−（４３０゜Ｆ−）への重量％転化率を、４：１の一定の触媒／油比で測定した。転化率を、スチーム失活時間の関数として図３にプロットして示している。
【００８１】
図２に示す表面積保持によれば、３種の触媒がすべて同等の骨格構造安定性を有することが示唆される種々の水熱失活条件において、Ｖ／ＵＳＹ触媒及びＲＥ＋Ｖ／ＵＳＹ触媒は同等の表面積保持率を呈することが示されている。しかし、図３に示す転化率のプロットは、水熱失活の苛酷度が増大する場合に、ＲＥ＋Ｖ／ＵＳＹ触媒ははるかに向上した分解活性の保持率を有することを示している。水熱失活において、分解活性をＶ／ＵＳＹからＲＥ＋Ｖの型（ｖｅｒｓｉｏｎ）へ向上させることは、１５％の転化率であった。種々の量のセリウムを有するＲＥの型どうしにおいても、明らかな違いは観察されなかった。これらの結果は、ＲＥ＋Ｖ／ＵＳＹ触媒がＶ／ＵＳＹ触媒よりも低い触媒／油比にて目標転化率を達成する、実施例８の場合に合致している。これらの転化率の結果は、ＲＥ＋Ｖ／ＵＳＹ触媒は、Ｖ／ＵＳＹ触媒に比べて、より安定であり、より良好な分解活性を保持するということを示している。ＵＳＹ触媒へ希土類元素イオンを添加した後、スチーム処理焼成してゼオライトのユニット・セル・サイズを低下させることによって、バナジウムの存在下では触媒の安定性が向上した。
【００８２】
実施例１０
シリーズ３触媒の流動床式接触分解の評価
実施例３からのＶ触媒及びＣｅ＋Ｖ ＵＳＹ触媒（触媒Ｉ、Ｊ）を、上記実施例４で説明したように、５０％スチーム及び５０％ガスを用いて、流動床スチーマーにおいて、７７０℃（１４２０゜Ｆ）で２０時間スチーム失活させ、空気燃焼（酸化的−終了）にて終了した。スチーム処理した添加物触媒の２５重量％を、低金属ＦＣＣ平衡触媒（１２０ｐｐｍのＶ及び６０ｐｐｍのＮｉ）に配合した。配合した触媒は、その後、上述のように、ＶＧＯＮｏ．１フィードを用いて、ＭＡＴ試験によって評価した。ＶＧＯＮｏ．１を使用するシリーズ３触媒の性能を表１０にまとめて示すが、生成物の選択率は、一定の転化率、２２０℃（４３０゜Ｆ）又はそれ以下の物質へのフィードの７０重量％の転化率へ補間した。
【００８３】
【表１０】

【００８４】
表１０は、繰り返しスチーム失活処理（酸化的−終了）の後、平衡ＦＣＣ触媒（Ｅ触媒）とそれぞれ配合したＶ／ＵＳＹ触媒及びＣｅ＋Ｖ／ＵＳＹ／シリカ−アルミナ−クレイ触媒のＦＣＣ性能を対比している。Ｅ触媒の基本のケースと対比して、Ｖ／ＵＳＹ触媒及びＣｅ＋Ｖ／ＵＳＹ触媒を添加することによって、生成物収率構造全体について多少の変化がもたらされている。Ｃ_４−ガス、ガソリン、軽質燃料油比及び重質燃料油の収率についても多少の変化が観察されている。水素及びコークスの収率について適度の増加が観察された。生成物の収率の変化は小さかったが、Ｖ／ＵＳＹ触媒及びＣｅ＋Ｖ／ＵＳＹ触媒はガソリンＳ濃度を実質的に変化させた。平衡ＦＣＣ触媒に、触媒Ｉ（Ｖ／ＵＳＹ対照触媒）２５重量％を配合すると、２９％のガソリン硫黄濃度の低下が達成された。対照的に、Ｃｅ＋Ｖ／ＵＳＹ触媒（触媒Ｊ）は、ガソリンＳの５６％の低下をもたらした。Ｖ／ＵＳＹ触媒へＣｅを添加することによって、ガソリンＳ含量を２７％低下させ、従って、Ｖ／ＵＳＹ対照触媒よりも９３％もの向上が達成された。双方の触媒は同等のバナジウム添加率（０．３９％対０．４３％のＶ）を有している。Ｃｅそれ自体はガソリンの硫黄低減活性を有していない（下記の実施例１１参照）という事項を考慮すると、これらの結果はまったく予期されなかったことであり、セリウムを添加することの利点（又は効果）を明確に示している。
【００８５】
実施例１１
繰り返しスチーム処理の後でのシリーズ４触媒の流動床式接触分解評価
この実施例では、実施例４からのＶ及びＣｅ＋Ｖ触媒の性能をまとめて示す。シリーズ４の触媒を、上記実施例４で説明したように、繰り返しスチーム処理（還元的−終了）によってスチーム失活させ、２５：７５の重量比で低金属ＦＣＣ平衡触媒（１２０ｐｐｍのＶ及び６０ｐｐｍのＮｉ）に配合し、ＶＧＯＮｏ．１フィードを用いて試験した。結果を表１１にまとめて示す。
【００８６】
【表１１】

【００８７】
表１１は、繰り返しスチーム失活処理（酸化的−終了）の後、Ｖ／ＵＳＹ触媒及びＣｅ＋Ｖ／ＵＳＹ／シリカ−アルミナ−クレイ触媒のＦＣＣ性能を対比している。Ｅ触媒の基本のケースと対比して、Ｖ／ＵＳＹ触媒及びＣｅ＋Ｖ／ＵＳＹ触媒を添加することによって、生成物収率構造全体について多少の変化がもたらされている。水素、Ｃ_４−ガス、ガソリン、軽質サイクル油、重質燃料油及びコークスの収率についても、それぞれ０．２重量％以下の変化が観察されている。Ｖ／ＵＳＹ触媒及びＣｅ＋Ｖ／ＵＳＹ触媒を添加することによって、ガソリンＳ濃度は種々の程度で変化した。平衡ＦＣＣ触媒に、触媒Ｋ（Ｖ／ＵＳＹ対照触媒）２５重量％を配合すると、５．２％のガソリン硫黄濃度の低下が達成された。対照的に、Ｃｅ＋Ｖ／ＵＳＹ触媒（触媒Ｍ及びＮ）は、それぞれガソリンＳの１７．４％の低下をもたらした。Ｖ／ＵＳＹ触媒へＣｅを添加することによって、ガソリンＳ含量を更に１２．３％低下させ、従って、Ｖ／ＵＳＹ対照触媒よりも２３７％もの向上が達成された。
【００８８】
実施例１２
繰り返しスチーム処理の後でのシリーズ４触媒の流動床式接触分解評価
この実施例では、実施例４からのＶ及びＣｅ＋Ｖ触媒の、繰り返しスチーム処理の後で性能をまとめて示す。シリーズ４の触媒を、上記実施例４で説明したように、繰り返しスチーム処理（還元的−終了）によって失活させ、２５：７５の重量比で低金属ＦＣＣ平衡触媒（１２０ｐｐｍのＶ及び６０ｐｐｍのＮｉ）に配合した。ＶＧＯＮｏ．１フィードを用いて得られた結果を表１２にまとめて示す。
【００８９】
【表１２】

【００９０】
表１２は、繰り返しスチーム失活処理（酸化的−終了）の後、Ｖ／ＵＳＹ及びＣｅ＋Ｖ／ＵＳＹ／シリカゾル添加物触媒のＦＣＣ性能を対比している。Ｅ触媒の基本のケースと対比して、Ｖ／ＵＳＹ及びＣｅ＋Ｖ／ＵＳＹ触媒を添加することによって、生成物収率構造全体について多少の変化がもたらされている。水素及びコークスの収率についても、適度の変化が観察された。Ｃ_４−ガス収率、ガソリン、軽質サイクル油、重質燃料油についても、多少の変化が観察された。Ｖ／ＵＳＹ触媒及びＣｅ＋Ｖ／ＵＳＹ触媒を添加することによって、ガソリンＳ濃度は実質的に変化した。平衡ＦＣＣ触媒に、触媒Ｋ（Ｖ／ＵＳＹ対照触媒）２５重量％を配合すると、５１．１％のガソリン硫黄濃度の低下が達成された。対照的に、Ｃｅ＋Ｖ／ＵＳＹ触媒（触媒Ｌ及びＭ）は、それぞれガソリンＳの５８．１％及び６１．３％の低下をもたらした。Ｖ／ＵＳＹ触媒へＣｅを添加することによって、ガソリンＳ含量を更に７．０〜１０．２％低下させ、従って、Ｖ／ＵＳＹ対照触媒よりも２０％までの向上が達成された。
【００９１】
Ｖ／ＵＳＹ触媒及びＣｅ＋Ｖ／ＵＳＹ触媒の生成物収率のデータは、Ｅ触媒からの収率の変化が、ＵＳＹ触媒へのバナジウムの添加に基づくものであることを示している。Ｖ／ＵＳＹ触媒の生成物収率は、ガソリンＳレベル以外の点で、Ｃｅ＋Ｖ／ＵＳＹ触媒の収率に匹敵する。これらの結果は、ＣｅがＶ／ＵＳＹ添加物触媒のガソリン硫黄低減活性を向上させて、生成物収率にはあまり影響を与えないということを示唆している。
【００９２】
実施例１３
シリーズ５触媒の流動床式接触分解評価、促進作用の検討
この実施例では、実施例５からのＣｅ及びＣｅ＋Ｖ触媒の、繰り返しスチーム失活処理（還元的−終了）の後での性能をまとめて示す。失活させた触媒を２５：７５の重量比で低金属ＦＣＣ平衡触媒（１２０ｐｐｍのＶ及び６０ｐｐｍのＮｉ）に配合した。ＶＧＯＮｏ．１フィードを用いて得られた結果を表１３にまとめて示す。
【００９３】
【表１３】

【００９４】
表１３は、繰り返しスチーム失活処理（還元的−終了）の後、Ｃｅ／ＵＳＹ及びＣｅ＋Ｖ／ＵＳＹ／シリカ−クレイ添加物触媒のＦＣＣ性能を対比している。Ｅ触媒の基本のケースと対比して、Ｃｅ／ＵＳＹ触媒を添加しても、生成物収率構造全体についてほとんど変化がなかった。Ｃｅ＋Ｖ／ＵＳＹ触媒を添加すると、生成物収率構造全体について多少の変化があった。水素及びコークスの収率について、並びにＣ_４−ガス、ガソリン、軽質サイクル油、重質燃料油の収率についても、適度の変化が観察された。Ｃｅ／ＵＳＹ触媒を添加することによって、ガソリンＳ濃度は変化しなかった。対照的に、Ｃｅ＋Ｖ／ＵＳＹ触媒（本発明の触媒Ｐ及びＱ）を添加することによって、ガソリンＳ濃度は、それぞれ２９．８％及び２７．７％低下した。これらの結果は、セリウムそれ自体はガソリン硫黄低減活性をまったく有さないということを示している。セリウムは、バナジウムに対して、Ｖ／ＵＳＹガソリン硫黄低減添加物触媒の活性を向上させる促進作用を有することが観察される。
【００９５】
実施例１４
循環式ライザーパイロット装置（Ｄａｖｉｓｏｎ Ｃｉｒｃｕｌａｔｉｎｇ Ｒｉｓｅｒ）において、ＶＧＯＮｏ．３フィード（表８）を用いて、典型的なＦＣＣ平衡触媒と組み合わせて、触媒Ｒの評価を行った。評価の前に、ＲＥ＋Ｖ／ＵＳＹ触媒は、５０％スチーム及び５０％ガスを用いて、７７０℃（１４２０゜Ｆ）で２０時間スチーム失活させた。ＦＣＣ装置からの平衡触媒（５３０ｐｐｍのバナジウム及び３３０ｐｐｍのＮｉ）に２５重量％のスチーム処理した添加物触媒を配合した。
触媒のＦＣＣ性能を表１４にまとめて示しており、生成物の選択率は、一定の転化率、２２０℃−（４３０゜Ｆ−）物質への７５重量％転化率へ補間した。
【００９６】
【表１４】

【００９７】
基本のケースと比較して、ＲＥ＋Ｖ／ＵＳＹ触媒２５重量％を添加すると、生成物収率構造全体について多少の変化があった。水素及びコークスの収率については無視できる程度の増加であった。Ｃ_４−ガス、ガソリン、軽質サイクル油、重質燃料油の収率についても、わずかに変化が観察された。ＲＥ＋Ｖ／ＵＳＹ触媒を添加することによって、ガソリン硫黄濃度は実質的に変化し、ガソリン硫黄濃度の２０％の低下が達成された。ガソリン硫黄濃度の低下に加えて、ＬＣＯについても実質的に硫黄の減少が観察され、全体としてＬＣＯ硫黄９％の減少に相当した。
ＬＣＯにおける硫黄種を表１５及び図４に示す。ＬＣＯは幅広いベンゾチオフェン及びジベンゾチオフェン硫黄種を含有している。硫黄の低減は、置換ベンゾチオフェン及び置換ジベンゾチオフェン、例えば、Ｃ_３＋−ベンゾチオフェン及びＣ_１〜Ｃ_４＋ジベンゾチオフェンにおいてより顕著であった。置換ジベンゾチオフェンはより嵩高く、ＦＣＣにおいて脱硫したり、分解したりするのは困難であると考えられていたため、この結果は全く予想されないものであった。
【００９８】
【表１５】

【００９９】
実施例１５
Ｃｅ＋Ｖ／ＵＳＹ／シリカゾル触媒の流動床式接触分解の評価
循環流動床式接触分解装置において、表８の苛酷に水素処理を行ったＦＣＣフィード（ＣＦＨＴフィード）を用いる典型的なＦＣＣ触媒と組み合わせて、４０日間で実施例７からのＣｅ＋Ｖ／ＵＳＹ触媒（触媒Ｓ）の評価を行った。ベースのＦＣＣ平衡触媒は、非常に低い金属レベル（２００ｐｐｍのＶ及び１３０ｐｐｍのＮｉ）を有している。最初の１５日間では、新たなＦＣＣ触媒と実施例７からのＣｅ＋Ｖ／ＵＳＹ触媒との５０／５０の割合の配合物をＦＣＣ再生装置に、１日あたり１．４％の触媒量で添加した。１５日目から４０日目では、新たなＦＣＣ触媒とＣｅ＋Ｖ／ＵＳＹ触媒との８５／１５の割合の配合物をＦＣＣ再生装置に、１日あたり１．４％の触媒量で添加した。再生装置の温度は、評価の間は約７０５℃（１３００゜Ｆ）に維持した。１種はＣｅ＋Ｖ／ＵＳＹ触媒を添加する前のもの（基本のケース）であり、もう１種は４０日目のものである、２種の触媒（Ｅ触媒）の試料をサンプリングした。Ｃｅ及びＶ分析に基づいて、Ｃｅ＋Ｖ／ＵＳＹ触媒の添加率を１２％と見積もった。
触媒のＦＣＣ性能を表１６にまとめて示しており、生成物の選択率は、一定の転化率、２２０℃−（４３０゜Ｆ−）物質への７０重量％転化率へ補間した。
【０１００】
【表１６】

【０１０１】
Ｅ触媒の基本のケースと比較して、Ｃｅ＋Ｖ／ＵＳＹ触媒を添加すると、生成物収率構造全体について多少の変化があった。水素及びコークスの収率については無視できる程度の増加であった。Ｃ_４−ガス、ガソリン、軽質サイクル油、重質燃料油の収率についても、わずかに変化が観察された。Ｃｅ＋Ｖ／ＵＳＹ触媒を添加することによって、ガソリンＳ濃度は実質的に変化した。平衡ＦＣＣ触媒に１２重量％のＣｅ＋Ｖ／ＵＳＹ触媒を配合すると、ガソリン硫黄濃度の２１％の低下が達成された。ガソリン硫黄濃度の低下に加えて、ＬＣＯ及びＨＦＯについても実質的に硫黄の減少が観察された。
硫黄ＧＣを用いて、軽質ＬＣＯフラクションにおける硫黄種の分析を行った。軽質ＬＣＯについての各有機硫黄種の濃度を、表１７及び図５にそれぞれ示す。
【０１０２】
【表１７】

【０１０３】
図５に示すように、軽質ＬＣＯは、主としてベンゾチオフェン硫黄種を含有している。硫黄の減少は、軽質ＬＣＯ硫黄全体として２７％の減少に相当し、置換ベンゾチオフェン、例えばＣ_１−ベンゾチオフェンからＣ_３＋−ベンゾチオフェンまでについてより顕著であった。置換ベンゾチオフェンはより嵩高く、ＦＣＣにおいて脱硫したり、分解したりするのは困難であると考えられていたため、この結果は全く予想されないものであった。
重質ＬＣＯフラクションにおける硫黄種を、表１８及び図６に示す。重質ＬＣＯは、主としてジベンゾチオフェン硫黄種を含有している。硫黄の減少（重質ＬＣＯについて全体として１４％）は、置換ジベンゾチオフェン、例えばＣ_１〜Ｃ_４＋−ジベンゾチオフェンについてより顕著であった。置換ジベンゾチオフェンはより嵩高く、ＦＣＣにおいて脱硫したり、分解したりするのは困難であると考えられていたため、この結果は全く予想されないものであった。
【０１０４】
【表１８】

【０１０５】
硫黄低減触媒は、ベンゾチオフェン及びジベンゾチオフェンの低減、並びにチオフェン硫黄種の低減に活性を有する。硫黄の減少は、置換ベンゾチオフェン及び置換ジベンゾチオフェンについて顕著に生じる。これらの結果は、アルキル置換チオフェンにおけるＣ−Ｓ結合はより反応性を有し、分解を受けやすいということを示唆している。
【０１０６】
置換チオフェン、置換ベンゾチオフェン、及び置換ジベンゾチオフェンの硫黄が容易に減少されることはまったく予想されなかったことであって、その後のＬＣＯ脱硫プロセスの効率を向上させることになる。ＬＣＯ脱硫プロセスについて、ベンゾチオフェン及びジベンゾチオフェンのメチル及び／又はアルキル置換は、有機硫黄種の脱硫反応性を実質的に低下させ、「ハードな硫黄」又は「耐熱性の硫黄」をもたらすということはよく知られている。本発明のより低い含量にて置換ベンゾ及びジベンゾチオフェンを含有するＬＣＯによれば、常套のＦＣＣ触媒によって製造される同等のＬＣＯと比較して、水素化脱硫プロセスの後でより低い硫黄含量を有するディーゼル燃料が製造されることになる。
【図面の簡単な説明】
【図１】図１は、硫黄ＧＣの種分化を伴なうＬＣＯ硫黄ＧＣを示している。
【図２】図２は、失活させた触媒の表面積の保持を示す。
【図３】図３は、スチーム失活時間の関数としての転化率を示している。
【図４】図４は、ＬＣＯにおける硫黄種を示している。
【図５】図５は、軽質ＬＣＯについての各有機硫黄種の濃度を示している。
【図６】図６は、重質ＬＣＯフラクションにおける硫黄種を示している。[0001]
The present invention relates to reducing sulfur in gasoline and other petroleum products produced by catalytic cracking processes. The present invention provides a catalyst composition for reducing product sulfur, and a method of using the composition to reduce product sulfur.
[0002]
Catalytic cracking is an oil refining process that is applied industrially on a very large scale, especially in the United States, where most of the refined gasoline blended pools are produced by catalytic cracking, most of which are fluidized bed It has been obtained by a catalytic cracking (FCC) process. In this catalytic cracking process, the heavy hydrocarbon fraction is converted to lighter products by reactions that take place at elevated temperatures in the presence of the catalyst, with the majority of the conversion or cracking reaction taking place in the gas phase. ing. The feedstock is converted to lighter gaseous cracked products having 4 or less carbon atoms per molecule, as well as gasoline, distillates, and other liquid cracked products. The gas consists partly of olefins and partly of saturated hydrocarbons.
[0003]
During the cracking reaction, a somewhat heavier substance known as coke adheres to the catalyst. This reduces the catalytic activity and requires regeneration. After removing the occluded hydrocarbons from the spent cracking catalyst, the coke is burned to recover the activity of the catalyst, thereby performing regeneration. Thus, the three characteristic steps of catalytic cracking are: a cracking step to convert hydrocarbon compounds to lighter products, a stripping step to remove hydrocarbon compounds adsorbed on the catalyst, and a combustion of coke from the catalyst. It can be distinguished from the regeneration step to be removed. The regenerated catalyst is then reused in the cracking process.
[0004]
Usually, the feedstock for catalytic cracking contains sulfur in the form of organic sulfur compounds such as mercaptans, sulfides and thiophenes. The products of the cracking process tend to contain corresponding sulfur impurities, even if about half of the sulfur content is converted to hydrogen sulfide primarily by catalytic cracking of non-thiophene sulfur compounds during the cracking process. The distribution of sulfur in the cracked products depends on many factors, including the feedstock, the type of catalyst, the additives present, the conversion and other operating conditions; It tends to enter the light or heavy gasoline fraction and be sent to the product pool. With the increasing environmental regulations that apply to petroleum products, for example, in the Reformed Gasoline (RFG) regulations, sulfur oxides and other sulfur compounds in the air after the combustion process In response to concerns about emissions into the atmosphere, the sulfur content of the product was generally reduced. Reducing gasoline sulfur is not only important for SOx emissions, but also for sulfur poisoning of automotive catalytic converters. Sulfur poisoning of the catalytic converter can also create other emission problems, such as NOx.
[0005]
Environmental concerns have been broadly focused on the sulfur content of motor gasoline due to its prominent position as an automotive fuel for passenger cars in the United States. This interest includes light cycle oil (LCO) and fuel oil fractions (light fuel oil (LFO) and heavy fuel oil (HFO)) obtained from the catalytic cracking process. It has been extended to high boiling distillate fractions. For these products, hydrodesulfurization has long been used to reduce the sulfur level in the product fraction, and this operation has generally been considered to be effective. However, higher boiling fractions are less suitable for desulfurization operations than lower boiling fractions, as higher boiling points increase the heat resistance of sulfur compounds, especially substituted benzothiophenes. Methyl and / or alkyl substitution of benzothiophene and dibenzothiophene in the LCO hydrodesulfurization process has substantially reduced the desulfurization reactivity of organic sulfur, and they have been described as "hard sulfur" or "heat resistant". Sulfur ". LCO sulfur GC is shown in FIG. 1 along with sulfur GC speciation. According to the evaluation by Girgis and Gate (Ind. Eng. Chem., 30, 1991, 2021-2058), by substituting a methyl group at the 4-position or 4- and 6-positions, the desulfurization activity is significantly increased. It is reported to decline. Reported that activity was reduced on the order of 1 to 10 (M. Houalla et al., Journal of Catalysis, 61, 1980, 523-527). Lamure-Meille et al. Suggested that the low activity of methyl-substituted dibenzothiophenes was caused by steric hindrance of the alkyl group (Lamur-Meille et al., Applied Catalysis A: General 131, 1995, 143-157). Assuming that higher boiling catalytic cracking products are used as feeds for the hydrodesulfurization process, it is clear that these cracking fractions are likely to trigger a reduction in the rate of formation of more heat resistant organic sulfur compounds. Become.
[0006]
Attempts have been made to remove sulfur from the FCC feed by hydrotreatment before cracking commences. While very effective, this approach tends to increase costs, both in terms of equipment capital costs and operating costs, due to the large consumption of hydrogen. Other attempts have been made to remove sulfur from cracked products by hydrotreatment. Although also very effective, this process has the disadvantage that the octane, a valuable product, is lost when high octane olefins are saturated.
[0007]
From an economic point of view, it is desirable to remove the sulfur content in the cracking process itself, since it will effectively desulfurize the major components of the gasoline blending pool without additional processing. Various catalytic materials have been developed to remove sulfur during the FCC process cycle, but to date most of the development has focused on removing sulfur from regenerator flue gas. Was something. An early attempt developed by Chevron was to use an alumina compound as an additive to an inserted cracking catalyst to adsorb sulfur oxides in FCC regeneration towers; Sulfur compounds adsorbed in the process are released as hydrogen sulfide during cracking of the cycle and sent to the product recovery section of the unit where they are removed. See Krishna et al., "Additives Improve FCC Process, Hydrocarbon Processing", November 1991, pp. 59-66. Sulfur is removed from the flue gas from the regenerator, but the product sulfur levels are not significantly affected, if at all.
[0008]
Another technique for removing sulfur dioxide from regenerators is based on using magnesium-aluminum spinel as an additive to the charged catalyst circulating in the FCCU. Under the designation DESOX®, which is used as an additive in this process, this technology has had significant commercial success. Representative patents for such sulfur removal additives include U.S. Pat. Nos. 4,963,520; 4,957,892; 4,957,718; 982 and the like. However, again the product sulfur levels are not significantly reduced.
[0009]
Catalyst additives for reducing sulfur levels in liquid cracked products have been proposed by Wormsbecher and Kim in U.S. Patent Nos. 5,376,608 and 5,525,210. . It uses the decomposition catalyst additive of a Lewis acid supported on alumina to produce gasoline with reduced sulfur, but this system has not had significant commercial success. Thus, there has been a continuing need for additives that are effective in reducing the sulfur content of liquid catalytic cracking products.
[0010]
In U.S. patent application Ser. No. 09 / 144,607 (filed on Aug. 31, 1998; corresponding to Japanese Patent Application No. 11-245105), the applicants filed a request for sulfur in the liquid product of the cracking process. Disclosed are catalyst materials for use in catalytic cracking processes that can reduce the content. These sulfur reduction catalysts contain, in addition to the porous molecular sieve component, a metal in an oxidation state greater than 0 inside the pore structure of the molecular sieve. The molecular sieve is in most cases a zeolite and may be a large pore size zeolite, such as zeolite beta or zeolite USY, or a medium pore size zeolite, such as a zeolite having properties corresponding to ZSM-5. Non-zeolitic molecular sieves, such as MeAPO-5 and MeAPSO-5, and mesoporous crystalline materials, such as MCM-41, can also be used as molecular sieve components of the catalyst. Metals such as vanadium, zinc, iron, cobalt and gallium have been found to be effective in reducing sulfur in gasoline, with vanadium being the preferred metal. These materials, when used as stand-alone particulate additive catalysts, are used to treat hydrocarbon feedstocks in fluidized bed catalytic cracking (FCC) units, typically active catalytic cracking catalysts (typically faujasite, e.g., Used in combination with zeolite Y, especially zeolite USY), produces low sulfur products. Since the molecular sieve component of the sulfur reduction catalyst is itself an active cracking catalyst, such as zeolite USY, it is in the form of an integrated cracking / sulfur reducing catalyst system, for example, metals that provide sulfur reducing functionality, such as vanadium, zinc, It is also possible to use the sulfur-reducing catalyst in a form containing a sulfur-reducing molecular sieve component and USY as an active decomposition component, together with iron, cobalt and gallium and the like and matrix materials to be added, such as silica and clay. .
[0011]
Another consideration in the production of FCC catalysts is catalyst stability, especially hydrothermal stability. The cracking catalyst is stripped by steam during use, following reduction (in the cracking step), and then from the combustion of coke, carbon-rich hydrocarbons attached to the catalyst particles during the cracking step in the cycle. Exposure to repeated oxidative regeneration cycles that produce large amounts of steam. In the early stages of developing zeolite cracking catalysts, a low sodium content is necessary not only for optimal cracking activity but also for stability, and rare earth elements such as cerium and lanthanum are very hydrothermally stable. Was found. See, for example, "Fluid Catalytic Cracking with Zeolite Catalysts", Venuto et al., Marcel Dekker, New York, 1979, ISBN 0-8247-6870-1.
[0012]
Applicants have developed a catalytic material for use in a catalytic cracking process that can, among other things, improve the reduction of the sulfur content of the liquid product of the cracking process, including gasoline and middle distillate cracking fractions. In the sulfur reduction catalyst of the present invention, a metal component in an oxidation state larger than 0 is present in the pore structure of the molecular sieve component of the catalyst composition, and in this case, vanadium is also a preferred metal. In that respect, it is similar to the catalyst disclosed in the aforementioned US patent application Ser. No. 09 / 144,607. However, in the case of the present invention, the composition also contains one or more rare earth elements, preferably cerium. Applicant has found that the presence of the rare earth element improves the stability of the catalyst as compared to a catalyst containing only vanadium or other types of metal components, and in certain preferred cases, in particular, It has been found that when cerium is used as the rare earth element component, the presence of the rare earth element improves the sulfur reduction activity. This is surprising since rare earth metal cations do not themselves have sulfur reducing activity.
[0013]
The sulfur reduction catalysts of the present invention are usually matrixed zeolites in combination with an active cracking catalyst in a cracker, i.e., containing a catalyst based on faujasite zeolite, usually zeolite Y. It is used in combination with the conventional main components of the circulating cracking catalyst. In another aspect, the sulfur reduction catalyst may be used in the form of an integrated cracking / component sulfur reduction catalyst system.
[0014]
According to the present invention, the sulfur removal catalyst composition comprises (i) a metal in an oxidation state greater than 0 inside the pore structure of the molecular sieve, and (ii) a porous molecular sieve containing a rare earth element component. It becomes. The molecular sieve is in most cases a zeolite, which can be a large pore size zeolite, such as zeolite beta or zeolite USY, or a medium pore size zeolite, such as a zeolite having properties corresponding to ZSM-5. . Non-zeolitic molecular sieves, such as MeAPO-5 and MeAPSO-5, and mesoporous crystalline materials, such as MCM-41, can also be used as molecular sieve components of the catalyst. Metals such as vanadium, zinc, iron, cobalt and gallium are effective. If the selected molecular sieve material has sufficient cracking activity, the material can also be used as an active catalytic cracking catalyst, usually a faujasite such as zeolite Y, or the active cracking component has the active cracking component Regardless of whether or not it has decomposition activity by itself, it can be added and used.
[0015]
The catalyst composition of the present invention is used in a fluidized bed catalytic cracking (FCC) unit to produce low sulfur gasoline and other liquid products, such as light cycle oils, which can be used as low sulfur diesel blends or heating oils. Useful for treating hydrocarbon feedstocks. In addition to achieving a significant reduction in the sulfur content of the cracked gasoline fraction, the sulfur-reducing catalyst material of the present invention provides a light cycle oil and fuel oil product (light fuel oil and heavy fuel oil) sulfur level. Can also be reduced. Sulfur reduction in LCO occurs primarily for substituted benzothiophenes and substituted dibenzothiophenes, and removing these more refractory species will increase the efficiency of sulfur reduction in subsequent LCO hydrodesulfurization processes. . Reduction of HFO sulfur can improve the quality of coker products from oil to expensive coke.
[0016]
The mechanism by which the metal-containing zeolite catalyst composition removes the sulfur components normally present in cracked hydrocarbon products is not precisely understood, but this mechanism converts the organic sulfur compounds in the feed to inorganic sulfur. The conversion is thus a contacting process. In this process, zeolites or other molecular sieves are believed to provide shape selectivity through changes in pore size, and metal sites in the zeolites to provide sulfur species adsorption sites.
The drawing is a graph showing the performance of the sulfur reducing composition of the present invention described below.
[0017]
FCC process
The sulfur removal catalyst of the present invention is used as a catalytic component of a circulating inventory of the catalyst in a catalytic cracking process, which is nowadays most often a fluidized bed catalytic cracking (FCC) process. For convenience, the present invention will be described with respect to the FCC process, however, the additives of the present invention provide a conventional moving bed type (TCC) cracking process by appropriately adjusting the size of the granulate to suit the requirements of the process. Can also be used. Apart from adding the additives of the present invention to the catalyst inventory and some changes that can be made in the product recovery section, there is no particular change in the manner in which the process is performed, as described below. Thus, it is described in conventional FCC catalysts, for example, the original report by Venuto and Habib, "Fluid Catalytic Cracking with Zeroite Catalysts", Marcel Decker, New York, 1979, ISBN 0-8247-6870-1, and See, for example, "Fluid Catalytic Cracking Handbook" by Sadgebeigi, Gulf publ. Zeolite-based catalysts with faujasite cracking components can also be used, as described in many other sources, such as Co., Houston, 1995 ISBN 0-88415-290-1.
[0018]
The fluidized bed catalytic cracking process, in which a heavy hydrocarbon feed containing organosulfur compounds is cracked to lighter products, is more or less simply described in a recycle cracking process of a circulating catalyst, where the feed is 20- This is done by contacting a circulating fluid catalytic cracking catalyst consisting of particles having a size in the range of 100 microns. The key steps in the cycle process are:
(I) Use comprising contacting a feed with a source of regenerated hot cracking catalyst in a catalytic cracking zone operated at catalytic cracking conditions, typically a riser cracking zone, containing coke and removable hydrocarbon compounds. Catalytically cracking the feed by producing an effluent containing spent catalyst, as well as cracked products;
(Ii) discharging the effluent and separating it, usually in one or more cyclones, into a gaseous phase rich in decomposition products and a solids-rich phase containing spent catalyst;
(Iii) separating the gas phase as a product and rectifying it in a main column of the FCC and its associated auxiliary column to produce a liquid cracked product containing gasoline;
(Iv) the spent catalyst is stripped, usually with steam, to separate the stored hydrocarbon compounds from the catalyst and then oxidatively regenerate the stripped catalyst to remove the regenerated hot catalyst Generating and then recycling this regenerated catalyst to a cracking zone to crack further feed
It is.
[0019]
The feed to the FCC process is a high boiling feed, typically of mineral oil origin, typically having an initial boiling point of at least 290 ° C (550 ° F), often 315 ° C (600 ° F) or higher. . The cut point for FCC feeds in most refineries is at least 345 ° C (650 ° F). The end point varies depending on the precise characteristics of the feed or on the operating characteristics of the refinery. The feed may be a distillate whose endpoint is generally 550 ° C. (1020 ° F.) or higher, for example 590 ° C. (1095 ° F.) or 620 ° C. (1150 ° F.), or a resid (non-distillable) Material may be included in the feed, and the resid material may comprise all or most of the feed. Distillable feeds include straight run feeds such as gas oil, for example heavy or light atmospheric gas oil, heavy or light vacuum gas oil, and cracked feeds such as light coker gas oil or heavy coker gas oil. Is included. Hydrotreated feeds, such as hydrotreated gas oils, especially hydrotreated heavy gas oils, can also be used, but the catalysts of the present invention can provide significant reductions in sulfur, The first hydrogen treatment for reduction can be omitted. Even in such cases, degradability is still achieved.
[0020]
In the process of the present invention, by performing the catalytic cracking in the presence of a sulfur reducing catalyst, the sulfur content of the gasoline portion of the liquid cracking product is effectively brought to a lower and more acceptable level.
[0021]
The sulfur reduction catalyst of the present invention can be used in the form of a separate particulate additive that is added to the main cracking catalyst in the FCCU, or it can be used as a material to provide an integrated cracking / sulfur reduction catalyst system. It can also be used as a component. The cracking component of the catalyst has been conventionally present and performs the formation and cracking reaction of the desired lower boiling point cracking product, and is usually based on the active cracking component of faujasite zeolite, For example, calcined rare-earth exchanged type zeolite (CREY) of the type calcined and exchanged with a rare earth element (CREY) (the production method thereof is disclosed in US Pat. No. 3,402,996), US U.S. Pat. No. 3,293,192 discloses an ultrastable Y zeolite (USY), and U.S. Pat. Nos. 3,607,043 and 3,676,368. Conventional in the form of one of the various partially exchanged types of Y zeolite, etc. Zeolite Y. Such cracking catalysts are widely and widely available from various commercial suppliers. Actively decomposing components provide clay and other materials such as silica or alumina to impart desired mechanical properties (such as abrasion resistance) and to control the activity of one or more highly active zeolite components. It is routinely combined with a matrix material. The particle size of the cracking catalyst is generally in the range of 10 to 100 microns for effective fluidization. When used as a separate particulate additive, the sulfur reducing catalyst (and all other additives) usually reduces the particle size and density of the cracking catalyst to prevent the components from separating during the cracking cycle. It is selected to have comparable particle size and density.
[0022]
Sulfur reduction system-molecular sieve component
According to the invention, the sulfur reduction catalyst comprises a porous molecular sieve having a metal in an oxidation state higher than 0 inside the pore structure of the molecular sieve. The molecular sieve is in most cases a zeolite, a zeolite with a large pore size, for example zeolite beta, preferably zeolite USY or zeolite beta, or a zeolite with properties corresponding to medium pore size zeolite, for example ZSM-5, Often, the former type is preferred.
[0023]
The molecular sieve component of the sulfur reduction catalyst of the present invention may be a zeolite molecular sieve or a non-zeolitic molecular sieve, as described above. When zeolites are used, large pore zeolites or medium pore zeolites (Frilette et al., J. Catalysis 67, 218-222 (1981)). The classification can be selected from Chen et al., "Shape Selective Catalysis in Industrial Applications", Marcel Deckker, New York, 1989, ISBN 0-8247-7856-1. Small pore sized zeolites, such as zeolite A and erionite, are not stable enough to be used in the catalytic cracking process, and in addition to not only the components of the cracking feed, but also many of the components of the cracking products. It is generally not preferred because of the molecular size rejection properties of the tendency to reject. However, the pore size of the molecular sieve, as shown below, is the same as the mesoporous crystalline material such as MCM-41, and the intermediate pore size zeolite and large pore size zeolite are both effective. Since it was found, it is not considered very important.
[0024]
Zeolites that have properties consistent with the presence of a large pore (12-membered ring) structure that can be used to form the sulfur reduction catalysts of the present invention include Y, REY, CREY, USY (among others) And zeolite L, zeolite beta, mordenite, including dealuminated mordenite, and other zeolites, such as zeolite ZSM-18. In general, large pore zeolites are characterized by a pore structure having an annular opening of at least 0.7 nm, while medium or medium pore zeolites have pore openings smaller than 0.7 nm but larger than 0.56 nm. Will have. Intermediate pore size zeolites suitable for use include pentasil-type zeolites such as ZSM-5, ZSM-22, ZSM-23, ZSM-35, ZSM-50, ZSM-57, MCM-22, MCM-49, MCM-56 and the like, all of which are known materials. Zeolites may be used with skeletal metal elements other than aluminum, for example, boron, gallium, iron, chromium.
[0025]
The use of zeolite USY allows this zeolite to be commonly used as the active cracking component of a cracking catalyst, thus allowing the sulfur reducing catalyst to be used in the form of an integrated cracking / sulfur reducing catalyst system Therefore, it is particularly preferable. USY zeolite used as a cracking component can also be advantageously used as an independent granular molecular sieve component for an added catalyst since the USY zeolite also contributes to the cracking activity of the entire catalyst present in the apparatus. The stability correlates with the small unit cell size of the USY, and for best results, the UCS (unit cell size) for the USY zeolite in the final catalyst is between 2.420 and 2.460 nm. , Preferably 2.420 to 2.455 nm, preferably 2.435 to 2.440 nm. After exposure to the repeated steaming of the FCC cycle, the UCS drops to a final value, usually in the range of 2.420 to 2.430 nm.
[0026]
In addition to zeolites, other types of molecular sieves may be used, although some acidic activity (as routinely measured by the alpha value) may be required for optimal performance. Molecular sieves are less preferred. The test data show that for metal free molecular sieves, alpha values above 10 are suitable for adequate desulfurization activity, and alpha values in the range of 0.2 to 2,000 are usually suitable. . (The alpha test is a convenient method for measuring total acidity, including the internal and external acidities of solid materials, such as molecular sieves. This test is described in US Pat. No. 3,354,078. And in Journal of Catalysis, Vol. 4, 527 (1965); 6, 278 (1966); and 61, 395 (1980). The alpha values reported in this specification were measured at a constant temperature of 538 ° C.) Alpha values of 0.2 to 300 are typical of the acidic activity of these materials when used as additives. Indicates the range.
[0027]
Representative non-zeolitic molecular sieve materials that can provide suitable support components for the metal component of the sulfur reduction catalyst of the present invention include silicates of various silica-alumina ratios, such as metallosilicates and titanosilicates. ), Metalloaluminates (e.g., germanium aluminate), metallophosphates, aluminophosphates, e.g., metal-integrated aluminophosphates (MeAPO and ELAPO), silico- and metalloaluminophosphates, metal-integrated silicoaluminophosphates ( MeAPSO and ELAPSO), silicoaluminophosphate (SAPO), gallogermanate and combinations thereof. For a study on the relationship between the structures of SAPO, AlPO, MeAPO and MeAPSO, see Stud. Surf. Catal. 37 13-27 (1987). AlPO contains aluminum and phosphorus, while SAPO has some of phosphorus and / or both phosphorus and aluminum replaced by silicon. In MeAPO, various metals, such as Li, B, Be, Mg, Ti, Mn, Fe, Co, An, Ga, Ge, and As, are present in addition to aluminum and phosphorus, while MeAPSO is further doped with silicon. including. The negative charge of the MeaAlbPcSidOe lattice (latice) is offset by cations, where Me is magnesium, manganese, cobalt, iron and / or zinc. MexAPSO is described in U.S. Pat. No. 4,793,984. SAPO type molecular sieve materials are described in U.S. Pat. No. 4,440,871 and MeAPO type catalysts are described in U.S. Pat. Nos. 4,544,143 and 4,567,029. As described, ELAPO catalysts are described in U.S. Pat. No. 4,500,651 and ELAPSO catalysts are described in European Patent Application 159,624. Specific molecular sieves are described, for example, in the following patents: MgAPSO or MAPSO in US Pat. No. 4,758,419; MnAPSO in US Pat. No. 4,686,092; CoAPSO in US Pat. No. 4,744,970; FeAPSO is described in U.S. Pat. No. 4,683,217; and ZnAPSO is described in U.S. Pat. No. 4,935,216. Specific silicoaluminophosphates that can be used include SAPO-11, SAPO-17, SAPO-34, SAPO-37, and other types of specific molecular sieve materials include MeAPO-5, MeAPSO-5. included.
[0028]
Another class of crystalline support materials that can be used is the group of mesoporous crystalline materials exemplified by MCM-41 and MCM-48 materials. These mesoporous crystalline materials are described in U.S. Patent Nos. 5,098,684, 5,102,643, and 5,198,203. MCM-41 is described in U.S. Pat. No. 5,098,684, which has a uniform diameter of at least 1.3 nm and a hexagonal (or hexagonal) array. The microstructure of the pores is characterized by an X-ray diffraction pattern having at least one lattice spacing d (d-spacing) greater than 1.8 nm after firing, and a d100 value greater than 1.8 nm ( This corresponds to a lattice spacing d of peaks in the X-ray diffraction pattern). The preferred catalyst form of this material is aluminosilicate, but other metal silicates may also be used. MCM-48 has a cubic structure and is manufactured by a similar manufacturing procedure.
[0029]
Metal component
To form the catalyst composition of the present invention, two metal components are incorporated into the molecular sieve support material. One component is a rare earth element such as lanthanum or a mixture of rare earth elements such as cerium and lanthanum. The other component is considered to be the primary sulfur reducing component, but its effect on sulfur reduction is less clear, as discussed in US patent application Ser. No. 09 / 144,607. For a description of a sulfur reduction catalyst composition containing vanadium and other metal components useful for the purposes of the present invention, reference is made to this specification by reference to its disclosure. For convenience, this component of the composition is referred to in the present application as the first sulfur reducing component. This metal must be present within the pore structure of the molecular sieve component to be effective. Metal-containing zeolites and other molecular sieves include (1) post-addition of metals to molecular sieves or catalysts containing one or more molecular sieves, (2) metal atoms in the framework structure It can be produced by synthesizing one or more molecular sieves and (3) synthesizing one or more molecular sieves having bulky metal ions trapped in the pores of the zeolite. After adding the metal component, it is necessary to perform washing, drying and firing to remove unbound ionic species. These techniques are known per se. Post-addition of metal ions is preferred from the point of view of simplicity and economy, and the available molecular sieve material is converted so that it can be used in the additive of the present invention. A wide variety of post-metal addition methods can be used to prepare the catalysts of the present invention, including aqueous exchange of metal ions, solid state exchange using one or more metal halide salts. Immersion using a solution of a metal salt, and vapor deposition of a metal can be used. In any case, however, it is important that the addition of the one or more metals is such that the metal component can enter the pore structure of the molecular sieve component.
[0030]
When the metal of the first sulfur reducing component is present as an exchanged cationic species in the pores of the molecular sieve component, the hydrogen transfer activity of the metal component is such that for the preferred metal component, the hydrogen transfer reaction that occurs during the cracking process is It has been found to reduce to the point where it is normally maintained at an acceptably low level. Thus, during cracking, coke and light gases increase slightly, but remain within acceptable limits. In any event, the unsaturated light components can be used as an alkylation feed, and thus can be recycled to the gasoline pool, thus reducing the gasoline range of hydrocarbons resulting from the use of the additives of the present invention. There is almost no loss.
[0031]
Metals incorporated into the additive should not exhibit significant hydrogenation activity, with fear that excess coke and hydrogen will be formed during the cracking process. For this reason, noble metals such as platinum and palladium having strong hydrogenation-dehydrogenation functions are not preferred. Base metals and combinations of base metals having a strong hydrogenation function, such as nickel, molybdenum, nickel-tungsten, cobalt-molybdenum, and nickel-molybdenum are not preferred for similar reasons. Preferred base metals are metals of the fourth period, groups 5, 8, 9, 12, 13 of the periodic table (IUPAC classification, formerly groups VB, VIII, IIB and IIIA). Vanadium, zinc, iron, cobalt and gallium are preferred metal components, and vanadium is a preferred metal component. Vanadium is usually considered to have a very serious effect on zeolite cracking catalysts, and much effort has been put into developing vanadium inhibitors, so that vanadium has thus been used in FCC catalyst compositions. What can be used is surprising. For example, Wormsbecher et al., "Vanadium Poisoning of Cracking Catalyst: Mechanism of Poisoning and Design of Vanadium Tolerant Catalyst." See Catalysis 100, 130-137 (1986). Placing vanadium within the pore structure of the molecular sieve fixes the vanadium and also prevents vanadium from becoming a vanadate species that can bind harmfully to the molecular sieve components; The sulfur reduction catalyst based on the zeolite of the invention and containing vanadium as the metal component retains the characteristic zeolite structure and exhibits a different environment for the metal while reducing and oxidizing / steaming conditions typical of the FCC cycle. It is thought to withstand repeated cycles.
[0032]
Vanadium is particularly suitable for reducing gasoline sulfur when supported on zeolite USY. The yield structure of the V / USY sulfur reduction catalyst is of particular interest. Other zeolite convert gasoline to C3 and C4 gases while the sulfur reduction of the gasoline is performed after the metal is added. Although the majority of the converted C3 = and C4 = can be alkylated and returned to the gasoline pool for re-compounding, the high yield of C4-wet gas indicates that many purifiers require their wet This can be problematic because it is limited by the capacity of the gas compressor. USY containing metals has a yield structure similar to current FCC catalysts. This advantage allows the content of V / USY zeolite in the catalyst formulation to be tailored to the target desulfurization level without being limited by the constraints of the FCC unit. Therefore, vanadium in the Y zeolite catalyst is a particularly preferred combination with zeolite represented by USY for reducing gasoline sulfur in FCC. USY that has been found to give particularly good results is in the range of 2.420 to 2.460 nm, preferably 2.420 to 2.450 nm, for example 2.435 to 2.450 nm (subsequent processing). USY with unit cell size. As the first sulfur reducing component, a combination of a base metal such as vanadium / zinc is also preferable from the viewpoint of the overall sulfur reduction.
[0033]
The amount of the first sulfur-reducing metal component in the sulfur-reducing catalyst is usually from 0.2 to 5% by weight (as metal, based on the weight of the molecular sieve component), generally from 0.5 to 5% by weight. However, even if the amount exceeds this range, for example, from 0.10 to 10% by weight, a certain sulfur reduction effect can be obtained. When the molecular sieve is matrixed, the amount of the first sulfur-reducing metal component, based on the total weight of the catalyst composition, will generally be from 0.1 to 5% by weight of the total catalyst, for practical purpose formulations. More generally, it will be 0.2 to 2% by weight.
[0034]
The second metal component of the sulfur reduction catalyst comprises one or more rare earth metals present in the pore structure of the molecular sieve, and is in the form of cations exchanged on exchangeable sites present in the molecular sieve component Is believed to exist. The rare earth (RE) component significantly improves catalyst stability in the presence of vanadium. For example, using a RE + V / USY catalyst can achieve a higher cracking activity compared to a V / USY catalyst, while providing comparable gasoline sulfur reduction. Rare earth elements of the lanthanoid series with atomic numbers 57-71, such as lanthanum, cerium, dysprosium, praseodymium, samarium, europium, gadolinium, ytterbium, and lutetium can be used in this way, but in view of commercial availability. From lanthanum and mixtures of cerium and lanthanum are usually preferred. From the viewpoint of sulfur reduction and catalyst stability, cerium has been found to be the most effective rare earth element component, and therefore, it is preferable to use cerium. Good results can be obtained even when the rare earth element is used.
[0035]
The amount of rare earth element is generally 1 to 10% by weight of the catalyst composition, most often 2 to 5% by weight. Based on the weight of the molecular sieve, the amount of rare earth element is usually 2 to 20% by weight, most often 4 to 10% by weight, depending on the molecular sieve: matrix ratio. Cerium can be used in an amount of 0.1 to 10% by weight of the catalyst composition, usually 0.25 to 5% by weight, based on the molecular sieve 0.2 to 20% by weight, in most cases It becomes 0.5 to 10% by weight.
[0036]
The rare earth element component can be suitably incorporated into the molecular sieve component by exchanging on a molecular sieve, either in the form of unmatrixed crystals or in the form of matrixed crystals. When formulating compositions using the preferred USY zeolite sieve, a very effective incorporation procedure is to add rare earth ions to the USY molecular sieve (typically a unit cell size of 2.445 to 2.465 nm). Further steam firing reduces the USY unit cell size to a value typically in the range of 2.420 to 2.460 nm, and then adds the first metal component if it is not already present. That is. USY must have a low alkali metal (mainly sodium) content for stability and satisfactory decomposition activity, which usually does not exceed 1% by weight on molecular sieves, preferably 0.5% The ammonium exchange performed during the ultra-stabilization process ensures that the desired sodium level does not exceed the weight percent.
[0037]
The metal component is incorporated into the catalyst composition in such a way as to ensure that it enters the pore structure inside the molecular sieve. The metal can be incorporated directly into the crystal or into the matrixed crystal. When using the preferred USY zeolite as the molecular sieve component, this operation re-fires the USY cracking catalyst containing the rare earth element component to ensure a small unit cell size, as described above, after which the metal ions are converted to the zeolite. It can be suitably incorporated by immersion under conditions that allow cation exchange to occur so that it can be fixed to the pore structure, or by ion exchange of metals, such as vanadium. In another aspect, the first sulfur reducing metal component and the rare earth metal component are incorporated into the molecular sieve component, for example, USY zeolite or ZSM-5 crystals, after performing the necessary calcination to remove organics from the composite. be able to. Thereafter, the metal-containing component can be formulated into a final catalyst composition by adding a decomposition component and a matrix component, and the formulation is formed into the final catalyst by spray drying.
[0038]
When the catalyst is formulated as an integrated catalyst system, the active cracking component of the catalyst, preferably faujasite, such as zeolite USY, is used for both simplicity of production and retention of controlled cracking characteristics. It is preferred to use the form as the molecular sieve component of the sulfur reduction system. However, other types of active cracking molecular sieve materials, such as zeolite ZSM-5, can also be incorporated into the integrated catalyst system, and such systems may have the properties of another active molecular sieve material, such as ZSM-5. It may be useful if desired. In each case, the impregnation / exchange process is performed with a controlled amount of metal, thus leaving the required number of sites on the molecular sieve to remove active degradation components, or any secondary Catalyzes a decomposition reaction that can be expected from a decomposition component such as ZSM-5.
[0039]
Use of sulfur reduction catalyst composition
Usually, the most convenient approach to using a sulfur reduction catalyst will be as an independent particulate additive to the catalyst. In a preferred embodiment, when zeolite USY is used as the molecular sieve component, adding a catalyst additive to the entire catalyst in the apparatus may result in a significant reduction in overall cracking due to the cracking activity of the USY zeolite. Will not be. The same applies when another active decomposition material is used as a molecular sieve component. When used in this manner, the composition can be used in the form of pure molecular sieve crystals, pelletized (without matrixing, with the added metal component) to the proper size for use in FCC. . However, usually, the metal-containing molecular sieve is matrixed in order to maintain sufficient fluidization and to obtain sufficient particle abrasion resistance. Conventional matrix materials for cracking catalysts, such as alumina or silica-alumina, together with the commonly added clay, are suitable for this purpose. The amount of matrix to molecular sieve can usually be from 20:80 to 80:20 by weight. Conventional matrixing techniques can also be used.
[0040]
The use of independent particulate additives allows the ratio of the sulfur reducing component and the cracking catalyst component to be optimized depending on the amount of sulfur in the feed and the desired degree of desulfurization. When used in this manner, it is generally used in an amount of 1 to 50% by weight of the total catalyst in the FCCU, and in most cases this amount will be 5 to 25% by weight, for example 5 to 15% by weight. . Approximately 10% is the standard for most practical applications. The additives can be added in a conventional manner, for example with the make-up catalyst to the regenerator or by any other convenient method. The additive remains active with respect to sulfur removal for a longer period of time, even though the sulfur removal activity may be impaired in a shorter time by a very high sulfur feed.
[0041]
Instead of using a separate particulate additive, a sulfur reduction catalyst can be incorporated into the cracking catalyst to form an integrated FCC cracking / gasoline sulfur reduction catalyst. When the sulfur-reducing component is used in combination with a molecular sieve other than the active decomposition component, for example, when the main active decomposition component is USY, when the sulfur-reducing component is used in ZSM-5 or zeolite beta, the sulfur-reducing component (molecular sieve) + Metal) will generally be up to 25% by weight or less of the total catalyst, corresponding to the amount that can be used as a separate particulate additive as described above.
[0042]
In addition to cracking catalysts and sulfur removal additives, other catalytically active components may be present in the circulating catalyst material. Examples of such other materials include octane boosting catalysts based on ZSM-5 zeolite, supported CO combustion promoters based on noble metals such as platinum, Desox (trade name) (magnesium-aluminum) Flue gas desulfurization additives such as spinel), vanadium trapping agents, and bottoms decomposition additives. These are described, for example, in Krishna, Sadhbeigi, supra, and Scherzer's "Octane Enhancing Zeolitic FCC Catalysts", Marcel Dekker, New York, 1991-90, NY, 1990-90. Is described in These components can be used in their usual usage amounts.
[0043]
The effect of the additives of the present invention is to reduce the sulfur content of liquid cracking products, especially light and heavy gasoline fractions, but the reduction of sulfur content reduces light cycle oils and light and heavy fuel oil fractions. It is also achieved in higher boiling distillate products, including by removing more refractory sulfur compounds, which can be applied to hydrodesulfurization technology. The distillate fraction is then hydrodesulfurized at less severe and more economical conditions to produce a distillate product suitable for use as a blending component in diesel or household fuel oils. Can be.
[0044]
The cracking process itself is carried out in the usual manner, with the addition of the sulfur reduction catalyst in the form of an additive or as an integrated catalytic cracking / sulfur reduction catalyst (single particulate catalyst). Decomposition conditions are essentially conventional.
[0045]
The sulfur separated during the cracking process by using a catalyst is converted to the form of an inorganic compound and released as hydrogen sulfide, which in the usual way is similar to the hydrogen sulfide normally released in the cracking process It can also be recovered in the product recovery section of the FCCU in a manner. Increased amounts of hydrogen sulfide may require additional sour gas / water treatment, but by reducing sulfur in gasoline to a significant extent, these are not likely to be limiting factors.
[0046]
By using the catalysts of the present invention, a significant reduction in the sulfur of the decomposition products can be achieved, and in some cases, with the preferred form of catalyst as described above, the basis for using conventional catalysts On a case-by-case basis, a reduction of up to 50% can be achieved at a constant conversion. Reducing sulfur in gasoline by 25% is easily achieved with many of the additives of the present invention, as shown in the examples described below. For middle distillate fractions, including the LCO fraction, reductions of up to 25% were achieved, as shown in the examples below, by combining with reduced levels of refractory sulfur compounds, including alkyl-substituted benzothiophenes and dibenzothiophenes. can do. The degree of sulfur reduction depends on the amount of organic sulfur compounds originally contained in the cracked feed, with the sulfur reduction being highest for feeds with higher sulfur content. The metal content of the equilibrium catalyst in the unit can also affect the degree of desulfurization achieved, and the lower the metal content in the equilibrium catalyst, especially the vanadium content, the greater the degree of desulfurization. If the vanadium content of the E-catalyst is less than 1000 ppm, the desulfurization becomes very effective, but even at higher vanadium contents the catalyst according to the invention remains effective. If the end point of the cracked gasoline in the refiner is limited by the sulfur content of the heavy gasoline fraction, reducing sulfur not only improves the quality of the product, but also improves the product yield. It is also effective for increasing. By providing an effective and economical way to reduce the sulfur content of heavy gasoline fractions, the end point of gasoline can be extended without having to resort to expensive hydroprocessing, thereby resulting in refinery This has a positive effect on the economics of the site. If subsequent hydrogen treatment is planned, it is also desirable to remove various thiophene derivatives that are difficult to remove by hydrogen treatment under less severe conditions.
[0047]
【Example】
Example 1
Preparation of Catalyst Series 1
All samples of Catalyst Series 1 were prepared from spray-dried single source material consisting of 50% USY, 21% silica sol and 29% clay. USY has a starting unit cell size of 2.454 nm, 5.46 SiO₂/ Al₂O₃Molar ratio, and 810 m²g^-1Of the total surface area.
The V / USY catalyst (catalyst A) is obtained by converting the above spray-dried catalyst to NH₄After slurried with OH, it was prepared by filtration, exchange of ammonium sulfate and washing with water. The catalyst was calcined at 1300 ° F. for 2 hours in the presence of steam to impregnate vanadyl oxalate. Steam firing reduced the unit cell size of the zeolite and increased the stability in the presence of vanadium.
[0048]
The V / USY catalyst (Catalyst B) was prepared in the same manner as Catalyst A, except that the initial slurrying of the catalyst was performed in the pH range of 3.2-3.5.
The two RE + V / USY catalysts (Catalysts C and D) exchanged the catalyst with a solution of rare earth chloride after ammonium sulfate exchange to give the catalyst 2% and 4% by weight RE, respectively.₂O₃Was prepared in the same manner as in Catalyst B except that was added. The rare earth element solution used was the Ce³⁺Has been extracted and therefore contains only some Ce ions.
[0049]
For the Ce + V / USY catalyst (Catalyst E), after ammonium sulfate exchange, the catalyst was exchanged with a solution of cerium chloride, and 5% of cerium was added to the catalyst (CeO2).₂) Was prepared in the same manner as in catalyst B, except that it was added.
These catalysts were then steamed to deactivate and the catalyst deactivated in the FCC unit using 50% steam for 20 hours at 770 ° C (1420 ° F) in a fluidized bed steamer. Simulated. Table 1 summarizes the physical properties of the calcined and steamed deactivated catalysts.
[0050]
[Table 1]

[0051]
Example 2
Preparation of Catalyst Series 2
V / USY catalyst (Catalyst F) was prepared using USY zeolite with a silica / alumina ratio of 5.4 and a unit cell size of 2.435 nm. The fluidized catalyst was prepared by spray drying an aqueous slurry containing 50% by weight USY crystals in a silica sol / clay matrix. The matrix contained 22% by weight silica sol and 28% by weight kaolin clay. The spray-dried catalyst is replaced with a solution of ammonium sulphate to give NH₄ ⁺And then dried. The USY catalyst was impregnated with a solution of vanadium oxalate to a target V of 0.5% by weight.
[0052]
RE + V / USY catalyst (Catalyst G) was prepared using USY zeolite with a silica / alumina ratio of 5.5 and a unit cell size of 2.454 nm. USY is converted to NH by exchange with a solution of ammonium sulfate.₄ ⁺Was replaced. NH₄ ⁺The exchanged USY is then exchanged with a mixture of rare earth element chlorides to form a rare earth cation (eg, La).³⁺, Ce³⁺Etc.). The rare earth element solution used was the Ce³⁺Was extracted and thus contained only a small amount of Ce. The USY that had been subjected to RE exchange was further washed, dried, and fired at 760 ° C. (1440 ° F.) in the presence of steam in a rotary firing apparatus. The steam firing reduced the unit cell size of the zeolite to 24.40 ° and increased the stability due to the presence of vanadium. The fluidized catalyst was prepared by spray drying an aqueous slurry containing 50% by weight of RE-USY crystals in a silica sol / clay matrix. The matrix contained 22% by weight silica sol and 28% by weight kaolin clay. The spray-dried catalyst is replaced with a solution of ammonium sulphate to give NH₄ ⁺And then dried and fired at 540 ° C. (1000 ° F.) for 2 hours. Continue firing and VOSO to RE / USY catalyst₄The solution was impregnated.
[0053]
Catalyst H is mainly used for the exchange of USY₃Mixed RECl containing₃Was prepared using the same procedure as in the case of the catalyst G, except that the solution was used. Catalyst H was prepared using a commercial USY zeolite having a silica / alumina ratio of 5.5 and a unit cell size of 2.454 nm. USY is converted to NH by exchange with a solution of ammonium sulfate.₄ ⁺Was replaced. NH₄ ⁺The exchanged USY is then replaced with CeCl containing lanthanum.₃Replaced by The exchanged USY was further washed, dried, and fired at 760 ° C. (1440 ° F.) in the presence of steam in a rotary firing apparatus. Steam calcination reduced the zeolite unit cell size to 2.440 nm. The fluidized catalyst was prepared by spray drying an aqueous slurry containing 50% by weight of rare earth element containing USY crystals in a silica sol / clay matrix. The matrix contained 22% by weight silica sol and 28% by weight kaolin clay. The spray-dried catalyst is replaced with a solution of ammonium sulphate to give NH₄ ⁺And then dried and fired at 540 ° C. (1000 ° F.) for 2 hours. Continue firing and add VOSO to catalyst₄The solution was impregnated. Table 2 summarizes the physical properties of the calcined catalyst.
[0054]
[Table 2]

[0055]
Example 3
Preparation of Catalyst Series 3
The V / USY catalyst (Catalyst I) was prepared using H-USY zeolite (crystal) having a silica / alumina ratio of 5.4 and a unit cell size of 2.435 nm. The fluidized catalyst was prepared by spray drying an aqueous slurry containing 40% by weight USY crystals, 25% by weight silica, 5% by weight alumina, and 30% by weight kaolin clay. The spray dried catalyst was calcined at 540 ° C. (1000 ° F.) for 3 hours. The resulting H-USY catalyst was impregnated with a solution of vanadium oxalate by incipient wetness impregnation to a target V of 0.4% by weight. The impregnated V / USY catalyst was further calcined in air at 540 ° C. (1000 ° F.) for 3 hours. The final catalyst contains 0.39% V.
[0056]
The Ce + V / USY catalyst (Catalyst J) was prepared from the same spray dried H-USY catalyst intermediate as Catalyst I. The H-USY catalyst is prepared using Ce (NO₃)₃The solution was impregnated to achieve the targeted 1.5 wt% Ce addition. The obtained Ce / USY catalyst was air-fired at 540 ° C. (1000 ° F.) for 3 hours and then steam-treated at 540 ° C. (1000 ° F.) for 3 hours. The catalyst was then impregnated with the vanadium oxalate solution by incipient wetness impregnation to a target V of 0.4% by weight. The impregnated Ce + V / USY catalyst was further calcined in air at 540 ° C. (1000 ° F.) for 3 hours. The final catalyst contains 1.4% Ce and 0.43% V.
[0057]
[Table 3]

[0058]
Example 4
Preparation of Catalyst Series 4
All samples of Catalyst Series 4 were prepared from spray-dried single source material consisting of 50% USY, 21% silica sol and 29% clay. The starting material, USY, had a silica / alumina ratio of 5.4 and a unit cell size of 2.454 nm. The spray-dried catalyst has a pH of 6₄OH and (NH₄)₂SO₄Slurry using the solution of⁺Was removed, washed with water, and fired at 650 ° C. (1200 ° F.) for 2 hours.
[0059]
The V / USY catalyst (catalyst K) was prepared using the H-USY catalyst described above. The H-USY catalyst was brought to the target 0.5 wt% V by impregnating the vanadium oxalate solution using an incipient wetness impregnation method. The impregnated V / USY catalyst was further calcined in air at 650 ° C. (1200 ° F.) for 2 hours. The final catalyst contains 0.5% V.
[0060]
Ce + V / USY (catalyst L) was prepared using the H-USY catalyst described above. H-type USY catalyst is CeCl₃The solution was replaced with the above solution to obtain the target addition of 0.75% by weight of Ce. The resulting Ce / USY catalyst was calcined in air and impregnated with a vanadium oxalate solution using an incipient wetness impregnation method to a target V of 0.5% by weight. The impregnated Ce + V / USY catalyst was further calcined in air. The final catalyst contains 0.72% Ce and 0.52% V.
Ce + V / USY (catalyst m) is obtained by converting the above H-type USY catalyst to CeCl₃The solution was replaced with the above solution to obtain the target addition of 3% by weight of Ce. The resulting Ce / USY catalyst was calcined in air and impregnated with a vanadium oxalate solution using an incipient wetness impregnation method with a target of V of 0.5% by weight. The impregnated Ce + V / USY catalyst was further calcined in air. The final catalyst contains 1.5% Ce and 0.53% V.
[0061]
Ce + V / USY (catalyst N) was obtained from the H-type USY catalyst by the incipient wetness impregnation method.₃To a target of 1.5% by weight of Ce. The resulting Ce / USY catalyst was calcined in air and impregnated with a vanadium oxalate solution using an incipient wetness impregnation method with a target of V of 0.5% by weight. The impregnated Ce + V / USY catalyst was further calcined in air. The final catalyst contains 1.5% Ce and 0.53% V.
[0062]
The catalysts were then steamed to deactivate and in a fluid bed steamer at 770 ° C. (1420 ° F.) using 50% steam and 50% gas for 20 hours in an FCC unit. Simulated catalyst deactivation. The gas stream is converted from air to N₂, Propylene, and N₂Mixture, as well as N₂And circulated back to the air to simulate the coking / regeneration cycle of the FCC unit (repeated steaming). Two sets of deactivated catalyst samples were regenerated. For one batch of catalyst, the steam deactivation cycle was terminated by air combustion (oxidative-end) and for another batch of catalyst by propylene (reductive-end). The "reducing-finish" coke content is less than 0.05% C. Table 4 summarizes the physical properties of the calcined and steamed (oxidative-finished) catalyst.
[0063]
[Table 4]

[0064]
Example 5
Preparation of Catalyst Series 5
All samples of Catalyst Series 5 were prepared from spray-dried single source material consisting of 40% USY, 30% colloidal silica sol and 30% clay. The starting material, Form H-USY, had a bulk silica / alumina ratio of 5.4 and a unit cell size of 2.435 nm. The spray dried catalyst was calcined in air at 540 ° C. (1000 ° F.) for 3 hours.
The Ce / USY catalyst (Catalyst O) was prepared using the H-USY catalyst described above. The H-USY catalyst uses the incipient wetness impregnation method to target Ce (NO₃)₃The solution was impregnated. The obtained Ce / USY was air-baked at 540 ° C. (1000 ° F.) and then steamed at 540 ° C. (1000 ° F.) for 3 hours.
[0065]
Ce + V / USY catalyst (Catalyst P) was prepared from Catalyst O. The Ce / USY catalyst was impregnated into the vanadium oxalate solution by an incipient wetness impregnation method to a target V of 0.5% by weight. The impregnated Ce + V / USY catalyst was dried and calcined in air at 540 (1000 ° F.). The final catalyst contains 1.4% Ce and 0.49% V.
The Ce + V / USY catalyst (Catalyst Q) was prepared from Catalyst O at a pH of ３3 with the goal of adding 0.5% by weight of V₄Prepared by impregnation with a solution of The resulting Ce / USY catalyst was dried and calcined in air at 540 (1000 ° F.) for 3 hours. Table 5 summarizes the physical properties of the calcined catalyst.
[0066]
[Table 5]

[0067]
Example 6
Preparation of RE + V / USY / Silica Sol Catalyst
RE + V / USY catalyst (Catalyst R) was prepared using NaY zeolite with a silica / alumina ratio of 5.5 and a unit cell size of 2.465 nm. Zeolite Y is converted to NH by exchange with a solution of ammonium sulfate.₄ ⁺Replaced by NH₄ ⁺The exchanged zeolite Y is then exchanged with a rare earth cation (eg, La3 +, Ce3 +, etc.) by exchanging using a mixture of rare earth element chlorides, and most of the rare earth element chloride mixture solution is exchanged. Ce³⁺Was extracted and therefore the solution contained very little cerium. The RE-exchanged Y was further washed with water, dried, and fired at 705 ° C. (1300 ° F.) for 2 hours in the presence of steam. Steam firing reduced the unit cell size of the zeolite, and the presence of vanadium improved stability. The fluidized catalyst was prepared by spray drying an aqueous slurry containing 50% by weight of RE-USY crystals in a silica sol / clay matrix. The matrix contained 22% by weight silica sol and 28% by weight kaolin clay. The spray-dried catalyst is replaced with NH 4 by exchange with a solution of ammonium sulphate.₄ ⁺Replaced by The calcination was continued and the RE / USY catalyst was impregnated with the vanadium oxalate solution. Table 6 summarizes the physical properties of the calcined catalyst.
[0068]
[Table 6]

[0069]
Example 7
Preparation of Ce + V / USY / silica sol catalyst
The Ce + V / USY catalyst (Catalyst S) was prepared using a NaUSY zeolite having a silica / alumina ratio of 5.5 and a unit cell size of 2.454 nm. USY is converted to NH by exchange with a solution of ammonium sulfate.₄ ⁺Was replaced. NH₄ ⁺The exchanged USY is then replaced with cerium chloride and a small amount of rare earth ion other than cerium (eg, La).³⁺, Pr, Nd, Gd, etc.) by exchange with a solution containing³⁺Was replaced. The USY after the exchange of Ce was further washed, dried, and fired at 705 ° C. (1300 ° F.) for 2 hours in the presence of steam. Steam calcination reduced the unit cell size of the zeolite, and the presence of vanadium improved stability. The fluidized catalyst was prepared by spray drying an aqueous slurry containing 50 wt% Ce / USY crystals in a silica sol / clay matrix. The matrix contained 22% by weight silica sol and 28% by weight kaolin clay. The spray-dried catalyst is replaced with a solution of ammonium sulphate to give NH₄ ⁺And then dried and fired at 540 ° C. (1000 ° F.) for 1 hour. The calcination was continued and the Ce / USY catalyst was impregnated with the vanadium sulfate solution. Table 7 summarizes the physical properties of the calcined catalyst.
[0070]
[Table 7]

[0071]
Experimental procedure: Evaluation of decomposition performance
The FCCs of the catalysts of Examples 1 to 7 were evaluated, and the results are reported in Examples 8 to 15. The blended catalyst (sample + equilibrium catalyst) was tested for gas oil cracking activity and selectivity by the ASTM D-3907 modified ASTM Microactivity Test (MAT) using a vacuum gas oil (VGO) feed. Some of the added catalysts were evaluated in a forward ring riser pilot using vacuum gas oil and hydrotreated feed. Table 8 shows the compositions of the three VGO feeds and one severely catalytically hydrotreated feed (CFHT) used in these examples.
[0072]
[Table 8]

[0073]
A range of cracking conversions was obtained by varying the catalyst / oil ratio by running the reaction at 527 ° C. (980 ° F.). The cut points for the degraded product were as follows:
Gasoline C₅+ To 220 ° C (125 ° F to 430 ° F),
Light LCO 220 ° C to 310 ° C (430 ° F to 590 ° F),
Heavy LCO 310 ° C to 370 ° C (590 ° F to 700 ° F),
Light fuel oil (LFO) 220 ° C to 370 ° C (430 ° F to 700 ° F),
Heavy fuel oil (HFO) 370 ° C + (700 ° F +).
Gasoline range products from each mass balance were analyzed using sulfur GC (Gas Chromatography) (AED) to determine the gasoline sulfur concentration. To reduce experimental errors in sulfur concentration due to variations in gasoline distillation cut points, thiophene in synthetic crude has₄Sulfur species (excluding benzothiophene and higher boiling S species) ranging up to -thiophene were quantified and the sum was defined as "S in cut-gasoline".
To determine the sulfur content of the distillate fraction in the boiling range above the gasoline range (Examples 14 and 15), the synthetic crude was subjected to atmospheric distillation to separate gasoline. The bottom fraction was then further subjected to vacuum distillation to produce two LFO / LCO fractions (light LCO fraction and heavy LCO fraction), the HFO fraction. Sulfur species in LCO samples were quantified using a gas chromatograph equipped with a J & W 100mDB-petroleum column and a Sievers 3655B sulfur detector. The concentration of each LCO sulfur species was calculated based on the total sulfur content measured by the XPS method and the percentage of sulfur species from GC.
[0074]
Evaluation of fluidized bed catalytic cracking of series 1 catalyst
The catalyst from Example 1 was steam deactivated in a fluidized bed steamer at 770 ° C. (1420 ° F.) for 20 hours using 50% steam and 50% gas as described in Example 4 above, Terminated by air combustion (oxidative-finish). 25% by weight of the steamed additive catalyst was incorporated into an equilibrium catalyst with very low metal levels (120 ppm V and 60 ppm Ni) from the FCC unit. In the microactivity test, VGONo. Using No. 1, the catalytic cracking performance of the catalyst was evaluated. The catalyst performance is summarized in Table 9 and the product selectivity was interpolated to a constant conversion, feed conversion to a material at or below 430 ° F (220 ° C).
[0075]
[Table 9]

[0076]
For the catalyst / oil ratios in Table 9, the blends with deactivated V / USY and E catalysts have higher catalysts to achieve 65% conversion compared to the base case of 100% equilibrium catalyst. It has been shown to require an oil / oil ratio (catalyst / oil ratio of 3.3 to 3.0, i.e., a 10% reduction in activity). This is based on the lower cracking activity of the V / USY catalyst compared to the equilibrium catalyst. In contrast, adding the RE + V / USY catalyst does not increase the catalyst / oil ratio to achieve 65% conversion. These catalyst / oil ratio results indicate that the RE + V / USY catalyst retains better cracking activity and has better stability than the V / USY catalyst.
[0077]
The addition of V / USY and RE + V / USY catalysts, compared to the basic case of equilibrium catalysts, has led to some changes in the overall product yield structure. The hydrogen and coke yields are slightly increased. C₄Some changes have also been observed in gas, gasoline, light fuel oil ratios and heavy fuel oil yields. By adding the V / USY catalyst and the RE + V / USY catalyst, the gasoline S concentration has been substantially changed. When the equilibrium FCC catalyst was blended with catalyst A or B (V / USY control catalyst) at 25% by weight, respectively, reductions in gasoline sulfur concentration of 39.0% and 40.8% were achieved, respectively. When 25% by weight of RE + V / USY catalysts (Catalysts C and D) are added to the equilibrium catalyst, the reduction in gasoline sulfur concentration is comparable to the control catalyst (38-40%). The RE + V / USY catalyst containing Ce as the majority of the rare earth metal (Catalyst E) results in a 43.1% reduction in S of the gasoline, further reducing the gasoline S content by 4%, ie, V / It achieves a 10% improvement over the USY catalyst and the mixed RE + V / USY catalyst. The vanadium addition (0.36-0.39%) of all catalysts was comparable.
[0078]
These results indicate that the addition of the rare earth element improves the decomposition activity of the V / USY catalyst. Changes in the yield of decomposition products are minor. Among the rare earth ions, cerium has the unique property that the Ce + V / USY catalyst exhibits not only higher cracking activity but also improved gasoline sulfur reduction activity under fluidized bed catalytic cracking conditions. . Rare earth RE / USY catalysts without large cerium levels do not provide much advantage over V / USY catalysts for gasoline S reduction, while cerium uses V / USY or RE + V / USY catalysts ( Gasoline sulfur levels (those without high cerium levels) are further reduced.
[0079]
Evaluation of decomposition activity of Series 2 catalyst
The catalysts from Example 2 (Series 2 catalysts, Catalysts F, G, H) were steamed at 770 ° C. (1420 ° F.) for various times to compare catalyst stability. The catalyst was 2.3 hours, 5.3 hours, 10 hours, 20 hours using 50% steam and 50% gas (repeated steaming as described in Example 4 above, reductive-end). Steamed in a fluidized catalytic steamer for hours and 30 hours. The retention of the surface area of the deactivated catalyst is plotted in FIG.
[0080]
The test for the cracking activity of gas oil of the steam-deactivated catalyst was carried out by using vacuum gas oil (VGO) No. 2 (at least 2.6% by weight of sulfur) by the ASTM microactivity test (ASTM procedure D-3907). At a contact time of 30 seconds and a reaction temperature of 545 ° C. (980 ° F.), the weight percent conversion to 220 ° C .- (430 ° F.) was measured at a constant catalyst / oil ratio of 4: 1. Conversion is plotted in FIG. 3 as a function of steam quenching time.
[0081]
According to the surface area retention shown in FIG. 2, the V / USY catalyst and the RE + V / USY catalyst were comparable under various hydrothermal deactivation conditions, suggesting that all three catalysts had the same skeletal structure stability. It has been shown to exhibit surface area retention. However, the conversion plot shown in FIG. 3 shows that as the severity of hydrothermal deactivation increases, the RE + V / USY catalyst has a much improved retention of cracking activity. In hydrothermal deactivation, increasing the decomposition activity from V / USY to RE + V version was a 15% conversion. No obvious differences were observed between the RE types with varying amounts of cerium. These results are consistent with Example 8 where the RE + V / USY catalyst achieves the target conversion at a lower catalyst / oil ratio than the V / USY catalyst. These conversion results indicate that the RE + V / USY catalyst is more stable and retains better cracking activity than the V / USY catalyst. The stability of the catalyst in the presence of vanadium was improved by adding a rare earth ion to the USY catalyst followed by steaming and firing to reduce the unit cell size of the zeolite.
[0082]
Example 10
Evaluation of fluidized bed catalytic cracking of series 3 catalyst
The V and Ce + V USY catalysts from Example 3 (Catalysts I and J) were prepared at 770 ° C. (1420 ° C.) in a fluidized bed steamer using 50% steam and 50% gas as described in Example 4 above. F) Steam deactivated for 20 hours and terminated by air combustion (oxidative-end). 25% by weight of the steamed additive catalyst was blended into a low metal FCC equilibrium catalyst (120 ppm V and 60 ppm Ni). The compounded catalyst was then used as described above for VGO No. One feed was evaluated by the MAT test. VGO No. The performance of the Series 3 catalyst using 1 is summarized in Table 10 where the selectivity of the product is 70% by weight of the feed to a constant conversion, 220 ° C (430 ° F) or lower material. Interpolated to conversion.
[0083]
[Table 10]

[0084]
Table 10 compares the FCC performance of a V / USY catalyst and a Ce + V / USY / silica-alumina-clay catalyst each blended with an equilibrium FCC catalyst (E catalyst) after repeated steam deactivation treatments (oxidative-end). ing. The addition of V / USY and Ce + V / USY catalysts, as compared to the basic case of E catalysts, has resulted in some changes in the overall product yield structure. C₄Some changes have also been observed in gas, gasoline, light fuel oil ratios and heavy fuel oil yields. A modest increase in hydrogen and coke yield was observed. Although the change in product yield was small, the V / USY and Ce + V / USY catalysts substantially changed the gasoline S concentration. When 25% by weight of Catalyst I (V / USY control catalyst) was incorporated into the equilibrium FCC catalyst, a 29% reduction in gasoline sulfur concentration was achieved. In contrast, the Ce + V / USY catalyst (Catalyst J) resulted in a 56% reduction in gasoline S. By adding Ce to the V / USY catalyst, the gasoline S content was reduced by 27%, thus achieving a 93% improvement over the V / USY control catalyst. Both catalysts have comparable vanadium loadings (0.39% vs. 0.43% V). Given the fact that Ce itself does not have the sulfur reducing activity of gasoline (see Example 11 below), these results were entirely unexpected and the benefits of adding cerium (or Effect) is clearly shown.
[0085]
Example 11
Fluid bed catalytic cracking evaluation of Series 4 catalyst after repeated steaming
In this example, the performance of the V and Ce + V catalysts from Example 4 are summarized. The Series 4 catalyst was steam deactivated by repeated steaming (reduction-end) as described in Example 4 above, and a 25:75 weight ratio of low metal FCC equilibrium catalyst (120 ppm V and 60 ppm V Ni) and VGO No. Tested with one feed. The results are summarized in Table 11.
[0086]
[Table 11]

[0087]
Table 11 compares the FCC performance of the V / USY catalyst and the Ce + V / USY / silica-alumina-clay catalyst after repeated steam deactivation treatments (oxidative-end). The addition of V / USY and Ce + V / USY catalysts, as compared to the basic case of E catalysts, has resulted in some changes in the overall product yield structure. Hydrogen, C₄-Changes in the yields of gas, gasoline, light cycle oil, heavy fuel oil and coke of less than 0.2% by weight have each been observed. By adding the V / USY catalyst and the Ce + V / USY catalyst, the gasoline S concentration changed to various degrees. When 25% by weight of Catalyst K (V / USY control catalyst) was blended with the equilibrium FCC catalyst, a 5.2% reduction in gasoline sulfur concentration was achieved. In contrast, the Ce + V / USY catalysts (catalysts M and N) each resulted in a 17.4% reduction in gasoline S. By adding Ce to the V / USY catalyst, the gasoline S content was further reduced by 12.3%, thus achieving a 237% improvement over the V / USY control catalyst.
[0088]
Example 12
Fluid bed catalytic cracking evaluation of Series 4 catalyst after repeated steaming
In this example, the performance of the V and Ce + V catalysts from Example 4 are summarized after repeated steaming. The Series 4 catalyst was quenched by repeated steaming (reduction-end) as described in Example 4 above, and a 25:75 weight ratio of low metal FCC equilibrium catalyst (120 ppm V and 60 ppm Ni ). VGO No. Table 12 summarizes the results obtained using one feed.
[0089]
[Table 12]

[0090]
Table 12 compares the FCC performance of V / USY and Ce + V / USY / silica sol additive catalysts after repeated steam deactivation treatments (oxidative-end). The addition of V / USY and Ce + V / USY catalysts, as compared to the basic case of the E catalyst, has resulted in some changes in the overall product yield structure. Moderate changes were also observed in the yields of hydrogen and coke. C₄-Some changes were also observed in gas yield, gasoline, light cycle oil and heavy fuel oil. By adding the V / USY catalyst and the Ce + V / USY catalyst, the gasoline S concentration was substantially changed. When 25% by weight of Catalyst K (V / USY control catalyst) was blended with the equilibrium FCC catalyst, a 51.1% reduction in gasoline sulfur concentration was achieved. In contrast, the Ce + V / USY catalyst (Catalysts L and M) resulted in a 58.1% and 61.3% reduction in gasoline S, respectively. By adding Ce to the V / USY catalyst, the gasoline S content was further reduced by 7.0 to 10.2%, thus achieving up to a 20% improvement over the V / USY control catalyst.
[0091]
Product yield data for the V / USY and Ce + V / USY catalysts indicate that the change in yield from the E catalyst is based on the addition of vanadium to the USY catalyst. The product yield of the V / USY catalyst is comparable to that of the Ce + V / USY catalyst except at the gasoline S level. These results suggest that Ce enhances the gasoline sulfur reduction activity of the V / USY additive catalyst and does not significantly affect product yield.
[0092]
Example 13
Fluidized bed catalytic cracking evaluation of series 5 catalysts, examination of promoting action
This example summarizes the performance of the Ce and Ce + V catalysts from Example 5 after repeated steam deactivation treatment (reducing-end). The deactivated catalyst was blended with a low metal FCC equilibrium catalyst (120 ppm V and 60 ppm Ni) in a weight ratio of 25:75. VGO No. Table 13 summarizes the results obtained using one feed.
[0093]
[Table 13]

[0094]
Table 13 compares the FCC performance of the Ce / USY and Ce + V / USY / silica-clay additive catalysts after repeated steam deactivation treatments (reducing-end). Compared to the basic case of the E catalyst, the addition of the Ce / USY catalyst caused little change in the overall product yield structure. The addition of the Ce + V / USY catalyst caused some changes in the overall product yield structure. For the yields of hydrogen and coke,₄-Moderate changes were also observed in the yields of gas, gasoline, light cycle oil and heavy fuel oil. The addition of the Ce / USY catalyst did not change the gasoline S concentration. In contrast, the addition of Ce + V / USY catalysts (Inventive Catalysts P and Q) reduced gasoline S concentration by 29.8% and 27.7%, respectively. These results indicate that cerium itself has no gasoline sulfur reduction activity. Cerium is observed to have a promoting effect on vanadium to improve the activity of the V / USY gasoline sulfur reduction additive catalyst.
[0095]
Example 14
In the circulation type riser pilot device (Davison Circulating Riser), VGO No. Catalyst R was evaluated using three feeds (Table 8) in combination with a typical FCC equilibrium catalyst. Prior to evaluation, the RE + V / USY catalyst was steam deactivated at 770 ° C. (1420 ° F.) for 20 hours using 50% steam and 50% gas. Equilibrium catalyst (530 ppm vanadium and 330 ppm Ni) from an FCC unit was blended with 25 wt% steam-treated additive catalyst.
The FCC performance of the catalyst is summarized in Table 14 and the product selectivity was interpolated to a constant conversion, 75 wt% conversion to 220 ° C- (430 ° F-) material.
[0096]
[Table 14]

[0097]
Compared to the base case, the addition of 25% by weight of the RE + V / USY catalyst caused some changes in the overall product yield structure. Hydrogen and coke yields were negligible. C₄-Slight changes were also observed in gas, gasoline, light cycle oil and heavy fuel oil yields. By adding the RE + V / USY catalyst, the gasoline sulfur concentration was substantially changed and a 20% reduction in gasoline sulfur concentration was achieved. In addition to the reduction in gasoline sulfur concentration, a substantial reduction in sulfur was also observed for LCO, corresponding to a 9% reduction in total LCO sulfur.
Table 15 and FIG. 4 show the sulfur species in the LCO. LCO contains a wide range of benzothiophene and dibenzothiophene sulfur species. Sulfur reduction can be achieved by substituted and substituted dibenzothiophenes such as C₃+ -Benzothiophene and C₁~ C₄+ More prominent in dibenzothiophene. This result was completely unexpected, as the substituted dibenzothiophenes were considered to be bulkier and difficult to desulfurize or decompose in the FCC.
[0098]
[Table 15]

[0099]
Example 15
Evaluation of fluidized bed catalytic cracking of Ce + V / USY / silica sol catalyst
In a circulating fluidized bed catalytic cracker, the Ce + V / USY catalyst from Example 7 (Catalyst) in 40 days was combined with a typical FCC catalyst using a severely hydrotreated FCC feed (CFHT feed) as shown in Table 8. The evaluation of S) was performed. The base FCC equilibrium catalyst has very low metal levels (200 ppm V and 130 ppm Ni). In the first 15 days, a 50/50 blend of fresh FCC catalyst and the Ce + V / USY catalyst from Example 7 was added to the FCC regenerator at a catalyst level of 1.4% per day. From days 15 to 40, an 85/15 blend of fresh FCC catalyst and Ce + V / USY catalyst was added to the FCC regenerator at a catalyst level of 1.4% per day. The temperature of the regenerator was maintained at about 705 ° C (1300 ° F) during the evaluation. One sample was before the addition of the Ce + V / USY catalyst (basic case) and the other was on day 40, and samples of two catalysts (E catalyst) were sampled. Based on Ce and V analysis, the addition rate of Ce + V / USY catalyst was estimated to be 12%.
The FCC performance of the catalyst is summarized in Table 16 and the product selectivity was interpolated to a constant conversion, 70 wt% conversion to 220 ° C- (430 ° F-) material.
[0100]
[Table 16]

[0101]
There was some change in the overall product yield structure when the Ce + V / USY catalyst was added compared to the basic case of the E catalyst. Hydrogen and coke yields were negligible. C₄-Slight changes were also observed in gas, gasoline, light cycle oil and heavy fuel oil yields. The addition of the Ce + V / USY catalyst substantially changed the gasoline S concentration. The incorporation of 12% by weight Ce + V / USY catalyst with the equilibrium FCC catalyst achieved a 21% reduction in gasoline sulfur concentration. In addition to the reduction in gasoline sulfur concentration, a substantial reduction in sulfur was also observed for LCO and HFO.
Analysis of sulfur species in the light LCO fraction was performed using sulfur GC. The concentration of each organic sulfur species for light LCO is shown in Table 17 and FIG. 5, respectively.
[0102]
[Table 17]

[0103]
As shown in FIG. 5, light LCO contains mainly benzothiophene sulfur species. The reduction in sulfur corresponds to a 27% reduction in overall light LCO sulfur, and the substituted benzothiophene, e.g.₁-Benzothiophene to C₃It was more pronounced up to + -benzothiophene. This result was entirely unexpected, as the substituted benzothiophenes were thought to be bulkier and difficult to desulfurize or decompose in the FCC.
The sulfur species in the heavy LCO fraction are shown in Table 18 and FIG. Heavy LCO contains mainly dibenzothiophene sulfur species. The reduction in sulfur (14% overall for heavy LCO) is due to the substitution of substituted dibenzothiophenes such as C₁~ C₄+ -Dibenzothiophene was more pronounced. This result was completely unexpected, as the substituted dibenzothiophenes were considered to be bulkier and difficult to desulfurize or decompose in the FCC.
[0104]
[Table 18]

[0105]
Sulfur reduction catalysts are active in reducing benzothiophene and dibenzothiophene, as well as in reducing thiophene sulfur species. Sulfur reduction occurs significantly for substituted benzothiophenes and substituted dibenzothiophenes. These results suggest that the C—S bond in alkyl-substituted thiophenes is more reactive and susceptible to decomposition.
[0106]
It was not expected at all that the sulfur of substituted thiophenes, substituted benzothiophenes, and substituted dibenzothiophenes would be easily reduced, which would improve the efficiency of the subsequent LCO desulfurization process. For the LCO desulfurization process, it is noted that methyl and / or alkyl substitution of benzothiophene and dibenzothiophene substantially reduces the desulfurization reactivity of the organic sulfur species, resulting in "hard sulfur" or "refractory sulfur". well known. The lower content LCOs of the invention containing substituted benzo and dibenzothiophene have a lower sulfur content after the hydrodesulfurization process compared to equivalent LCOs produced with conventional FCC catalysts. Diesel fuel will be produced.
[Brief description of the drawings]
FIG. 1 shows LCO sulfur GC with sulfur GC speciation.
FIG. 2 shows the retention of the surface area of the deactivated catalyst.
FIG. 3 shows conversion as a function of steam quenching time.
FIG. 4 shows sulfur species in LCO.
FIG. 5 shows the concentration of each organic sulfur species for light LCO.
FIG. 6 shows sulfur species in the heavy LCO fraction.

Claims (33)

A method for reducing the sulfur content of a catalytically cracked petroleum fraction, comprising:
A liquid petroleum feed fraction containing organic sulfur compounds,
(I) comprising a metal vanadium in an oxidation state greater than 0 and comprising a first metal component present in a pore structure inside a molecular sieve; and (ii) at least one rare earth element; Catalytic cracking at elevated temperature in the presence of a cracking catalyst having a product sulfur reducing catalyst comprising a porous molecular sieve having a second metal component present in the pore structure inside the molecular sieve, and Producing a reduced liquid degradation product. Product sulfur reduction catalyst, as a molecular sieve component, The method of claim 1 comprising a large pore size zeolites or intermediate pore size zeolites. 3. The method of claim 2, wherein the large pore size zeolite comprises faujasite zeolite. 3. The method according to claim 2, wherein the second metal component comprises lanthanum alone or in combination with cerium. 3. The method of claim 2, wherein the second metal component comprises cerium. The method of claim 1, wherein the second metal component is present in an amount of 1 to 10% by weight of the catalyst composition. The product sulfur reduction catalyst comprises a USY zeolite having a UCS of 2.420-2.460 nm and a bulk silica: alumina ratio of at least 5.0 as the molecular sieve component, and cerium alone as the second metal component. Or the method according to claim 1, comprising a combination with a lanthanum. The method of claim 1 wherein the product sulfur reduction catalyst is a separate particulate additive catalyst. The process of claim 1 wherein the liquid decomposition product having a reduced sulfur content comprises a gasoline fraction, a cycle oil fraction, and a fuel oil fraction, wherein the cycle oil and the fuel oil have a higher boiling point than the gasoline fraction. The heavy hydrocarbon feed containing the organic sulfur compound is contacted with a flowable and circulating catalytic cracking catalyst having dimensions in the range of 20 to 100 microns in a catalytic cyclic cracking process to produce lighter products. A fluidized bed catalytic cracking method for catalytic cracking,
(I) Spent catalyst containing catalytically cracked feed containing coke and strippable hydrocarbons by contacting the feed with a source of regenerated cracking catalyst in a catalytic cracking zone operated at catalytic cracking conditions Producing a degradation zone effluent containing degradation products,
(Ii) discharging the effluent mixture and separating it into a phase rich in cracking catalytic cracking and a phase rich in solid matter containing spent catalyst;
(Iii) removing the vapor phase as a product and fractionating the vapor phase to produce a liquid decomposition product containing gasoline;
(Iv) stripping the spent catalyst-enriched solid phase to separate occluded hydrocarbons from the catalyst;
(V) transferring the stripped catalyst from the stripper to a catalyst regeneration device;
(Vi) regenerating the stripped catalyst by contacting it with an oxygen-containing gas to produce a regenerated catalyst;
(Vii) recycling the regenerated catalyst to the cracking zone and contacting it with a further heavy hydrocarbon feed, wherein the catalytic cracking comprises: (i) comprising metal vanadium in an oxidation state greater than 0; And (ii) a second metal component comprising at least one rare earth element and present in the pore structure inside the molecular sieve. A fluidized bed catalytic cracking method for reducing the sulfur content of a liquid cracked product by carrying out in the presence of a product sulfur reducing catalyst comprising a porous molecular sieve. Cracking catalyst The method of claim 1 0 further comprising a matrixed faujasite zeolite. Product sulfur reduction catalyst, as a molecular sieve component comprises a large pore size zeolites or intermediate pore size zeolites, as the second metal component及beauty, claim 1, comprising alone or in combination with at least one rare earth metal cerium The method of claim 1 . The method of claim 1 wherein the large pore size zeolite product sulfur reduction catalyst comprises a faujasite zeolite. The method of claim 1 0 further comprising a second metal component either alone or in combination with cerium lanthanum. The method of claim 1 0, wherein the second metal component comprises cerium. The method of claim 1 0, wherein the second metal component is present in an amount of 1 to 10 wt% of the catalyst composition. Liquid degradation products, reduced gasoline fraction of sulfur content, and have a boiling point higher than the gasoline fraction, the method of claim 1 0, further comprising a reduced cycle oil fraction of sulfur content. A catalyst composition for reducing the sulfur content of a fluid catalytic cracking product for reducing the sulfur content of a catalytically cracked gasoline fraction during a catalytic cracking process, comprising:
Have dimensions in the range of 20-100 microns,
(I) a porous molecular sieve component,
(Ii) a first metal component that is present in the internal pore structure of the porous molecular sieve component and includes a metal vanadium component in an oxidation state greater than 0; exist, flowable granulate comprise Do that catalytic composition comprising a second metal component comprising a rare earth metal into. 19. The catalyst composition for reducing a sulfur content of a fluid catalytic cracking product according to claim 18 , wherein the porous molecular sieve component is a porous molecular sieve component that decomposes hydrocarbons. 20. The fluid catalytic cracking product of claim 19 , wherein the porous molecular sieve component comprises a USY zeolite having a UCS of 2.420 to 2.460 nm and a bulk silica: alumina ratio of at least 5.0. Catalyst composition. 21. The fluid catalytic cracking product of claim 20 , wherein the porous molecular sieve component comprises a USY zeolite having a UCS of 2.420-2.435 nm and a bulk silica: alumina ratio of at least 5.0. Catalyst composition. Based on the weight of the zeolite, vanadium was added to the first metal component at 0 . 19. The catalyst composition for reducing the sulfur content of a fluid catalytic cracking product according to claim 18, which contains 1 to 5% by weight. The catalyst composition for reducing the sulfur content of a fluid catalytic cracking product according to claim 22 , comprising cerium and at least one rare earth element other than cerium as the second metal component. 19. The catalyst composition for reducing the sulfur content of a fluid catalytic cracking product according to claim 18, which contains cerium as the second metal component. 19. The catalyst composition for reducing the sulfur content of a fluid catalytic cracking product according to claim 18 , wherein the metal component has been introduced into the zeolite as an exchanged cationic species in the pores of the zeolite. 19. The catalyst composition for reducing the sulfur content of a fluid catalytic cracking product according to claim 18, formulated with a matrix component as a fluid cracking catalyst additive. Heavy by decomposing a hydrocarbon feed to produce liquid cracking products including gasoline, and contact the sulfur content of catalytic cracking and gasoline fraction during the decomposition process of integration reduces the flowability contact min Kaisei Narubutsu a yet that catalysts are formulated as a sulfur reducing catalyst, comprises flowable particulates hydrocarbon cracking component having a size ranging from 20 to 100 microns,
The hydrocarbon cracking component is a zeolite molecular sieve containing (i) a first metal component containing metal vanadium , and (ii) a second metal component containing at least one rare earth element, present in the zeolite pore structure. catalytic reducing the sulfur content of claim 20 fluidity catalytic cracking products according containing. 28. The integrated fluid catalytic cracking / product sulfur reduction catalyst of claim 27 , comprising from 0.1 to 5% by weight of vanadium as the first metal component, based on the weight of the zeolite. 28. The integrated fluid catalytic cracking product sulfur reduction of claim 27, wherein the second metal component comprises cerium and a combination of at least one rare earth element other than cerium in an amount of 1-5% by weight of the catalyst. catalyst. 28. The integrated fluid catalytic cracking product sulfur reduction catalyst of claim 27 , wherein the second metal component comprises a combination of cerium in an amount of 1-5% by weight of the catalyst. 28. The integrated fluid catalytic cracking product sulfur reduction catalyst of claim 27 , wherein the zeolite molecular sieve comprises a USY zeolite having a UCS between 2.420 and 2.460 nm and a bulk silica: alumina ratio of at least 5.0. 31. The fluid catalytic cracking product sulfur reduction catalyst of claim 30 , wherein the porous molecular sieve component comprises a USY zeolite having a UCS between 2.420 and 2.435 nm and a bulk silica: alumina ratio of at least 5.0. 28. The fluid catalytic cracking product sulfur reducing catalyst of claim 27 , formulated as a fluid cracking / sulfur reducing catalyst integrated with a faujasite zeolite as a cracking component and a matrix component.

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