ES2214971B1 - PROCEDURE FOR THE INERTIZATION AND CONDITIONING OF PASTRY WASTE RICH IN HYDROCARBONS BY MIXING WITH BIOMASS COMBUSTION ASHES. - Google Patents

Abstract

Procedure for the inertization and conditioning of pasty residues rich in hydrocarbons by mixing with biomass combustion ashes, by obtaining a mixture between pasty residues of hydrocarbons and ashes, in percentages between 40% and 70% of ashes with respect to weight wet from the mixture, and the rest of hydrocarbon residues. The minimum recommended contact time is twelve hours. It is thus possible to provide solid consistency to the mixtures, with granular appearance, facilitating their handling and storage under appropriate conditions, and at the same time promoting the inertization of the waste and facilitating its subsequent recycling. The mixture can be used as an agronomic acid corrective complement in sterile deposits of thermal power plants and other substrates.

Description

Procedure for inertization and conditioning of pasty residues rich in hydrocarbons by mixed with biomass combustion ashes.

The technical sector corresponds to treatment, inertization and promotion of waste recycling pasty consistency with the presence of significant amounts of hydrocarbons

Pasty residues rich in hydrocarbons, such as those derived from beach cleaning and coasts affected by spills of fuel, oil and products similar, present different problems. It may happen that such wastes are not suitable for use as fuels in thermal plants, because of the presence of significant quantities of solid impurities (eg sands) or limitations related to their starting characteristics (for example, too high sulfur contents, which can make unacceptable or inappropriate combustion for use energy in certain circumstances). In such case, it is It is necessary to have the logistics to ensure the evacuation of waste from sensitive areas from which they are removed (beaches and coasts) and subsequent storage and treatment. When the quantities to be stored are very high, as usual occur in cases of massive spills linked to accidents of High transport capacity ships, waste management pasty not subjected to inertization treatments and Additional conditioning can become a problem seriously, that aggravates the one caused by the spill itself in the sea.

Currently, this type of pasty waste They are usually stored temporarily in large rafts -principally of waste management companies- with capacity for thousands of tons and, if not finally burned in plants of energy use, we must try to find some appropriate means of conditioning and subsequent inertization, which it will be variable according to the particular characteristics of the residue, and for which there is no clear definition and protocol standardized standard applicable with probabilities of success.

The problem affects pasty waste, consisting of hydrocarbons, derived from ship discharges, that reach beaches and coasts, and are subsequently removed, with often emulsified with water and mixed with sands, algae...

These pasty residues may not always be used to generate energy by combustion, because of high content of solid impurities that accompany them, or due to other limitations or impediments of a physical or chemical nature. When this case occurs, the temporary storage of waste is It can become an additional serious problem. In fact, if the origin of the waste corresponds to a massive discharge, derived for example of an accident that has affected an elevated ship transport capacity, the availability of enclaves or appropriate facilities for the deposit of substances Problems can be complicated and insufficient. On the other hand, to lack of an exit through the use of energy, it will be it is necessary to propose some alternative treatment and conditioning, after having undertaken its storage temporary, since it could not be considered appropriate to stop promoting its inertization and recycling if feasible.

In this invention we propose solutions making the mixture of pasty residues, rich in hydrocarbons, with biomass combustion ashes, such as  that are derived from energy cogeneration plants linked to logging companies These ashes are currently considered a residue or by-product without economic value, characterized by pH purely alkaline (often in the pH range of 8.5 to 12.5) and for its richness in potassium, calcium, magnesium, phosphorus and others Nutrients usable by vegetables, although years has been trying to give way to large quantities accumulated by-product, promoting its use as acidity corrector and as a nutrient contribution in soils appropriate.

Making the mixtures in the proportions adequate, in a certain order, with a certain contact time it is possible to transform pasty hydrocarbon waste -Characterized by its adhesion, certain fluidity and sometimes for unpleasant odors, especially for the presence of sulfur compounds - in solid consistency materials, granules, which are easy to handle and store as solids, no need for containment rafts, with remarkable resistance Waterfront, with reduced odor and with characteristics physicochemicals that reduce their potential toxicity and that allow to consider its use and recycling as a complement of agronomic management in waste dumps or sterile deposits of combustion of thermal power plants, or even on certain substrates or floors of non-sensitive areas, mainly with low environments  risk of transmission of contamination. The potential use as agronomic complement of the resulting mixtures - mainly linked to the purely alkaline pH, which generally exceeds value of 10, and its content in potassium, calcium, magnesium, phosphorus  and other nutrients for vegetables - lets focus them as correctors for the acidity characteristic of sterile thermal, and favors substrate recovery strategies.

It is possible to mix hydrocarbon residues not only with biomass ashes but also add a certain proportion of some conventional whitewasher
-preferably commercial quicklime- of rather fine particle size, as supplied without difficulty in the market. In this way the characteristics of the final mixture can be improved in certain cases, both in terms of its consistency and its richness in calcium and its alkalinity (when it is interesting to increase the latter two).

It is also possible to use for mixing with hydrocarbon waste a material that has resulted from a previous process of mixing between biomass ashes and sludge wastewater treatment plant derivatives (having obtained that mixture of some waste manager or marketer of said authorized material, or by the team itself of treating hydrocarbon waste, after disposing of timely permits). The previous mixture between ashes and sludge residuals have the advantage of presenting a nitrogen content much larger than that of ashes alone (which sometimes even is null), in addition to higher organic content of relatively easy mineralization, which may contribute to a greater ease of recycling, by subsequent agronomic management, of the final mixtures that also incorporate the waste pasty rich in hydrocarbons.

The procedure to implement the mixtures between pasty residues rich in hydrocarbons and ashes (alone or in combination with quicklime or sludge residuals) will depend on the degree of automation desired Introduce in the process. Essentially a container is needed container for mixing, a hopper of dimensions suitable, preferably with turning and turning capacity to facilitate contact between components; and an area for temporary storage of mixtures. Tapes can be used conveyors to move the products to the hopper of mixed, however paying attention to adhesion characteristic of hydrocarbon waste. These means mechanics are common in the application of procedures conventional sludge stabilization from the wastewater treatment (Spanish patent P200200443). It is also appropriate to have a zone or silo of storage for ashes (alone or in combination with quicklime or with sludge), so that there are remnants available for mixed. In the same way, it is convenient to reserve a space for the reception and temporary storage of waste from hydrocarbons, for example in a raft waterproofed by its base and sides, and preferably protected from rainfall

Embodiment

Starting from the materials separately, the hydrocarbon residues and ashes alone or combined with lime live or with residual sludge, the two will be mixed products (using hopper, turner and conveyor belts  if necessary and according to the degree of automation desired to the process, not forgetting the adherent power of waste, which it can be partially solved by systematically arranging layers fine lime or ash on the conveyor belt of the pasty hydrocarbons), in proportions generally included between 40% and 70% of ashes with respect to wet weight of the mixture, and the rest of pasty hydrocarbon residues until the 100%, or between 35% ashes plus 5% lime live and 65% of ashes plus 5% of quicklime, and the rest waste hydrocarbon pastes up to 100%, or between 40% and 70% mixture of ashes and sewage sludge from wastewater (which must have been acquired or obtained previously under appropriate conditions, with authorizations corresponding), and the rest of pasty hydrocarbon residues up to 100%; although these proportions could be modified -without starting limitation - depending on the characteristics that are wish for the final product, such as consistency or pH

Frequently, the best result in terms of inertization corresponds to mixtures containing around 60% of ashes (alone or in combination with quicklime or residual sludge) and 40% of hydrocarbon residues (in wet weight of the mixture). Mixing will preferably be done by first adding a dose of the ashes (alone or in combination with quicklime or with residual sludge) to the hopper, followed by the corresponding dose of the residue, then proceeding to mechanical mixing, then adding a new dose of ashes (alone or combined with quicklime or with residual sludge) and then the corresponding proportion of the residue, then proceeding to a new mechanical mixing of the set, and so on until reaching the volume of mixing programmed by the process directors in situ . The mixtures obtained may be stored temporarily in available places, preferably protected from the impact of precipitation.

Regarding the response of the mixtures to contact with water, presents certain differences depending on the use of ashes alone or in combination with quicklime or sewage sludge, but in no case is a behavior that can be observed consider more worrying than the one presented by waste pasty of untreated hydrocarbons by means of mixing alternatives noted.

After a minimum contact time, about 12 hours, or preferably 24 hours if possible, mixtures acquire characteristics that will allow them to be used as agronomic management supplements, preferably for recovery of sterile or debris from thermal power plants, providing alkalinity, potassium, calcium, magnesium, phosphorus and others nutrients, to different substrates that can be favored by Receive the product.

Claims (3)

1. Procedure for inerting and conditioning pasty residues rich in hydrocarbons by mixing with biomass combustion ashes, characterized by mixing two components: one component is biomass combustion ashes, alone or in combination with quicklime or residual sludge, and the other component pasty residues rich in hydrocarbons; establishing a contact time between 12 and 24 hours; and the percentages between the components vary depending on their starting characteristics and the characteristics of the mixture that is intended to be achieved, which will preferably be comprised: a) Between 40% and 70% of combustion ashes of biomass; or between 35% of ashes plus 5% of quicklime and 65% of ashes plus 5% of quicklime; or between 40% and 70% mixture of ashes and sewage sludge sludge; all referred to wet weight of the mixture. b) Between 60% and 30% of pasty waste rich in hydrocarbons, referred to the wet weight of the mixture. 2. Mixture or mixtures according to claim 1, for the inertization and conditioning of waste from hydrocarbons that are part of these mixtures. 3. Mixture or mixtures according to the claims above, for use as an agronomic complement in the recovery of waste dumps or combustion tanks of thermal power plants or other substrates that can be seen their physical-chemical conditions improved.