CN108863770A - 一种乙酰丙酸制备及其溶剂和催化剂回收的工艺 - Google Patents

一种乙酰丙酸制备及其溶剂和催化剂回收的工艺 Download PDF

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CN108863770A
CN108863770A CN201810965325.1A CN201810965325A CN108863770A CN 108863770 A CN108863770 A CN 108863770A CN 201810965325 A CN201810965325 A CN 201810965325A CN 108863770 A CN108863770 A CN 108863770A
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李晓云
司传领
姚丽菲
梁敏
邱钰
蒋利杰
田雨扬
韩淑君
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Tianjin University of Science and Technology
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Abstract

本发明属于生物质化工技术领域,具体涉及一种乙酰丙酸制备及其溶剂和催化剂回收的工艺。该工艺主要包括以下步骤:HZSM‑5型分子筛与金属氯化物水溶液混合,油浴加热,使HZSM‑5型分子筛与金属离子进行充分的离子交换反应,冷却到室温后,对所得固体洗涤、干燥、焙烧、研磨,得到金属离子改性HZSM‑5催化剂。将得到的催化剂与葡萄糖混合,添加γ‑戊内酯/水溶液,加入高压反应釜,反应结束后进行固液分离,液体部分进行减压蒸馏,得乙酰丙酸。煅烧固体部分回收催化剂,从液体部分回收γ‑戊内酯。该工艺以金属离子改性HZSM‑5为催化剂,具有催化活性高、可循环使用的优点。其次以γ‑戊内酯为溶剂,可提高产物得率、降低反应温度,且此溶剂为绿色溶剂,环境友好。

Description

一种乙酰丙酸制备及其溶剂和催化剂回收的工艺
技术领域
本发明属于生物质化工技术领域,具体涉及一种乙酰丙酸制备及其溶剂和催化剂回收的工艺。
背景技术
乙酰丙酸是一种重要的平台化合物,以纤维素类碳水化合物为原料制备。乙酰丙酸能发生取代、酯化、氧化还原或者聚合反应。应用于γ-戊内酯(GVL)、5-氨基乙酰丙酸和2-甲基四氢呋喃(MTHF)的合成。乙酰丙酸也可用于缩酮生产,或者用作润滑剂或增塑剂。此外,乙酰丙酸可用于生产热固性塑料、多元醇和热塑性塑料。
制备乙酰丙酸的反应路径有两种。一种是C6糖直接水解法。此反应路径包括:C6糖在酸催化加热条件下水解成单糖(葡萄糖和果糖)、单糖发生脱水反应生成5-羟甲基糠醛,最后进一步反应生成乙酰丙酸。另一种是乙酰丙酸的生产从C5糖开始。反应过程由三个步骤组成。第一步是用酸催化木糖脱水生成糠醛。第二步是用金属催化糠醛还原成糠醇。最后一步是用布朗斯特酸催化糠醇生成乙酰丙酸。
目前,制备乙酰丙酸的反应条件为温度范围是140~225℃,在水溶液中强酸催化碳六糖(如葡萄糖、果糖)或者是纤维素、木质素纤维素生物质转化为乙酰丙酸和甲酸。最有效的酸性催化剂为盐酸、硫酸或者三氟乙酸,酸浓度范围为0.1~2.0mol/L。在工业的实际应用中,美国Biofine公司将废弃纤维素转化成乙酰丙酸工艺,采用稀硫酸为催化剂,生物质的经过系列酸脱水反应制备乙酰丙酸。
目前,乙酰丙酸是由纤维素类碳水化合物中的C6糖(或者纤维素)转化成的平台化合物。传统的乙酰丙酸生产工艺一般采用水为反应介质,矿物质酸为催化剂,但是,这些反应工艺存在产率低、能耗高、废水和废酸产量高等问题,因此,为缓解乙酰丙酸制备行业存在的这些问题,需要开发新型的乙酰丙酸反应体系。
发明内容
本发明的第一个目的是提供一种用于制备乙酰丙酸的金属离子改性HZSM-5催化剂的制备方法。
本发明的第二个目的是提供一种金属离子改性HZSM-5催化葡萄糖制备乙酰丙酸的工艺。
本发明的第三个目的是提供金属离子改性HZSM-5和γ-戊内酯的回收工艺。
本发明技术方案概述如下:
(1)将5~10g的HZSM-5型分子筛与100mL的1~10mmol/L的金属氯化物水溶液混合,油浴加热至60~90℃,搅拌处理6~12h,使HZSM-5型分子筛与金属离子进行充分的离子交换,冷却到室温,以200~500mL去离子水对所得固体进行洗涤2~6次,再在100℃条件下干燥8h,然后在550℃条件下焙烧4h,最后对焙烧后的固体研磨至粒径小于80目,得到金属离子改性HZSM-5催化剂;
(2)将金属离子改性HZSM-5催化剂与葡萄糖按质量比1∶10~10∶1混合,添加葡萄糖质量60~100倍的γ-戊内酯和水,混合均匀后,加入磁力搅拌的高压反应釜中,用氮气吹扫反应釜2~6次,并调节釜中压力至5MPa,在150~190℃温度下反应12~24h,反应结束后,反应釜放入冰水浴中冷却至室温,过滤反应后的混合物进行固液分离,液体部分进行减压蒸馏,得到乙酰丙酸;
(3)液体部分减压蒸馏后残余的部分采用二氧化碳超临界萃取法回收γ-戊内酯溶剂,在600℃煅烧固体部分5h回收金属离子改性HZSM-5催化剂。
上述方案中所述的金属氯化物为AlCl3、FeCl3、NiCl2、CuCl2中的一种或几种的混合物。
上述方案中所述的以金属离子改性HZSM-5催化葡萄糖转化为乙酰丙酸及其催化剂和溶剂回收的工艺,其特征在于,所述的添加的γ-戊内酯和水的体积比为19∶1。
本发明的显著优点是:
本发明具有反应条件温和、乙酰丙酸得率较高、操作简单和环保等优点。采用的溶剂为γ-戊内酯,以木质纤维素生物质为原料制备获得,是一种应用于木质纤维素生物质转化为有价值的平台化合物反应过程的绿色溶剂。将金属离子改性HZSM-5应用在碳水化合物制备乙酰丙酸的反应过程中,此种催化剂在水热条件下催化活性高、稳定性高、易回收等优点,具有工业化的应用前景。
具体实施方式
下面将以具体的实施例来对本发明作进一步详细的描述,但本发明不局限于这些具体实例。
实施例1:
(1)将6g的HZSM-5型分子筛与100mL的4mmol/L的AlCl3水溶液混合,油浴加热至70℃,搅拌处理8h,使HZSM-5型分子筛与金属离子进行充分的离子交换,冷却到室温,以300mL去离子水对所得固体进行洗涤4次,再在100℃条件下干燥8h,然后在550℃条件下焙烧4h,最后对焙烧后的固体研磨至粒径70目,得到金属离子改性HZSM-5催化剂;
(2)将金属离子改性HZSM-5催化剂与葡萄糖按质量比1∶2混合,添加葡萄糖质量75倍的γ-戊内酯和水,混合均匀后,加入磁力搅拌的高压反应釜中,用氮气吹扫反应釜4次,并调节釜中压力至5MPa,在160℃温度下反应16h,反应结束后,反应釜放入冰水浴中冷却至室温,过滤反应后的混合物进行固液分离,液体部分进行减压蒸馏,得到乙酰丙酸;
(3)液体部分减压蒸馏后残余的部分采用二氧化碳超临界萃取法回收γ-戊内酯溶剂,在600℃煅烧固体部分5h回收金属离子改性HZSM-5催化剂。
实施例2:
(1)将8g的HZSM-5型分子筛与100mL的8mmol/L的FeCl3水溶液混合,油浴加热至80℃,搅拌处理10h,使HZSM-5型分子筛与金属离子进行充分的离子交换,冷却到室温,以400mL去离子水对所得固体进行洗涤5次,再在100℃条件下干燥8h,然后在550℃条件下焙烧4h,最后对焙烧后的固体研磨至粒径60目,得到金属离子改性HZSM-5催化剂;
(2)将金属离子改性HZSM-5催化剂与葡萄糖按质量比2∶1混合,添加葡萄糖质量85倍的γ-戊内酯和水,混合均匀后,加入磁力搅拌的高压反应釜中,用氮气吹扫反应釜5次,并调节釜中压力至5MPa,在180℃温度下反应20h,反应结束后,反应釜放入冰水浴中冷却至室温,过滤反应后的混合物进行固液分离,液体部分进行减压蒸馏,得到乙酰丙酸;
(3)液体部分减压蒸馏后残余的部分采用二氧化碳超临界萃取法回收γ-戊内酯溶剂,在600℃煅烧固体部分5h回收金属离子改性HZSM-5催化剂。

Claims (3)

1.一种以金属离子改性HZSM-5催化葡萄糖转化为乙酰丙酸及其催化剂和溶剂回收的工艺,其特征是包括如下步骤:
(1)将5~10g的HZSM-5型分子筛与100mL的1~10mmol/L的金属氯化物水溶液混合,油浴加热至60~90℃,搅拌处理6~12h,使HZSM-5型分子筛与金属离子进行充分的离子交换,冷却到室温,以200~500mL去离子水对所得固体进行洗涤2~6次,再在100℃条件下干燥8h,然后在550℃条件下焙烧4h,最后对焙烧后的固体研磨至粒径小于80目,得到金属离子改性HZSM-5催化剂;
(2)将金属离子改性HZSM-5催化剂与葡萄糖按质量比1∶10~10∶1混合,添加葡萄糖质量60~100倍的γ-戊内酯和水,混合均匀后,加入磁力搅拌的高压反应釜中,用氮气吹扫反应釜2~6次,并调节釜中压力至5MPa,在150~190℃温度下反应12~24h,反应结束后,反应釜放入冰水浴中冷却至室温,过滤反应后的混合物进行固液分离,液体部分进行减压蒸馏,得到乙酰丙酸;
(3)液体部分减压蒸馏后残余的部分采用二氧化碳超临界萃取法回收γ-戊内酯溶剂,在600℃煅烧固体部分5h回收金属离子改性HZSM-5催化剂。
2.根据权利要求1所述的金属氯化物为AlCl3、FeCl3、NiCl2、CuCl2中的一种或几种的混合物。
3.根据权利要求1所述的以金属离子改性HZSM-5催化葡萄糖转化为乙酰丙酸及其催化剂和溶剂回收的工艺,其特征在于,所述的添加的γ-戊内酯和水的体积比为19∶1。
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110483269A (zh) * 2019-09-03 2019-11-22 天津科技大学 一种sapo-18催化葡聚糖制备乙酰丙酸的方法
CN115368324A (zh) * 2021-05-18 2022-11-22 南京林业大学 一种分子筛负载双金属催化纤维素降解转化成高附加值化学品的方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1680257A (zh) * 2005-01-07 2005-10-12 浙江大学 用分子筛催化水解葡萄糖制取乙酰丙酸的方法
CN104024238A (zh) * 2011-12-28 2014-09-03 纳幕尔杜邦公司 用于制备糠醛的方法
CN105525044A (zh) * 2015-08-12 2016-04-27 南京工业大学 一种在极性非质子体系中超低酸催化水解纤维素、半纤维素原料制备还原糖的方法
CN105906588A (zh) * 2016-05-13 2016-08-31 中盐安徽红四方股份有限公司 一种由糖制备5-羟甲基糠醛的方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1680257A (zh) * 2005-01-07 2005-10-12 浙江大学 用分子筛催化水解葡萄糖制取乙酰丙酸的方法
CN104024238A (zh) * 2011-12-28 2014-09-03 纳幕尔杜邦公司 用于制备糠醛的方法
CN105525044A (zh) * 2015-08-12 2016-04-27 南京工业大学 一种在极性非质子体系中超低酸催化水解纤维素、半纤维素原料制备还原糖的方法
CN105906588A (zh) * 2016-05-13 2016-08-31 中盐安徽红四方股份有限公司 一种由糖制备5-羟甲基糠醛的方法

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
卢崇兵等: "金属氯化物对高温液态水中葡萄糖分解反应动力学的影响", 《化工学报》 *
隋小玉等: "ZSM-5催化葡萄糖清洁转化合成乙酰丙酸", 《化学反应工程与工艺》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110483269A (zh) * 2019-09-03 2019-11-22 天津科技大学 一种sapo-18催化葡聚糖制备乙酰丙酸的方法
CN115368324A (zh) * 2021-05-18 2022-11-22 南京林业大学 一种分子筛负载双金属催化纤维素降解转化成高附加值化学品的方法

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