Optimisation of degraded Biodegradable Municipal Waste (BMW) products by enzymatic treatment

在印度，产生的城市固体废物（MSW）中只有25%经过处理并送往垃圾填埋场;而且那里的垃圾填埋场已经过度填充。因此，正在开发通过酶处理降解城市固体废物的有机部分以产生糖的方法。然后，这种有机部分（BMW）降解为糖，可以以较小的商业价值出售。然而，城市固体废物的不同组成可能会影响产品的产量-因此，通过最佳纤维来源找到“最佳”糖产量的优化过程将是重要的一步。然后，这些糖可能被转化为不同行业的各种高价值产品。乙酰丙酸糖的酸水解可以形成乙酰丙酸-一种可以合成多种有机化学品的物质。乙酰丙酸的酯化可以形成柴油混溶性燃料（DMB），其可以减少由化石燃料消耗产生的CO2（Fernandes et.等人，2012）。其他用途包括作为纺织品，树脂，增塑剂和防冻剂。有机酸或者，添加微生物可以使糖发酵，产生具有更大商业价值的有机酸（如乳酸）。在间歇式反应器中很难进行这一过程--因为有机酸会产生一种酸性环境，杀死微生物，从而停止这一过程。目前的研究一直在寻找基因工程微生物来抵抗酸性环境--然而这会提高运营成本。或者，在不改变微生物的情况下将其转化为连续过程可以解决很多问题-例如更大的转化率，停止有机酸的积累，并且是扩大该过程的必要步骤。运输燃料可以通过几种方式从BMW生产运输燃料：1）上面讨论的有机酸可以进行（生物）氢化，将其转化为醇，从而转化为生物燃料。2)糖可以发酵成乙醇和生物柴油。这些开发过程的每个阶段都需要特定的步骤：-基于模型的实验设计-过程扰动，以了解过程如何受到潜在问题或变化的影响-从批量转换为连续-过程建模-集成过程控制以测量和分析过程

Within India, only 25% of the Municipal Solid Waste (MSW) generated is processed and taken to landfill; and the landfills that are there are overfilling. Therefore, a process to degrade the organic fraction of the MSW by enzymatic treatment to produce sugars is under development. This organic fraction (BMW) then degrades to sugars which can be sold for a small commercial value. However, the different compositions of the MSW may affect the yields of the products - so an optimisation process to find the 'best' sugar yield through the best source of fibre present would be an important step. These sugars could then potentially then be converted into diverse high-value products for different industries.- Levulinic acidThe acid hydrolysis of sugars can form Levulinic acid - a substance that can synthesise several organic chemicals. The esterification of levulinic acid can form a diesel miscible fuel (DMB) that may decrease the CO2 generated from fossil fuel consumption (Fernandes et. al, 2012). Other uses include as a textile, resin, plasticiser and antifreeze.- Organic acidsAlternatively, the addition of microbes can ferment the sugars to produce organic acids (such as lactic acid) which have a greater commercial value. It is difficult to do this process in a batch reactor - as the organic acids produce an acidic environment which kill the microbes; stopping the process.Current research has been looking at genetically engineering the microbes to resist the acidic environment - however this would drive up operational costs. Alternatively, converting this to a continuous process without changing the microbes could solve a lot of issues - such as greater conversion, stopping the build-up of organic acids and is a necessary step for scale-up of the process.- Transport fuelsTransport fuels could be produced in several ways from the BMW:1) The organic acids discussed above can undergo (bio)hydrogenation to convert them into alcohols and so to biofuels. 2) The sugars can be fermented into ethanol and biodieselsEach stage of these developed processes would require certain steps:- Model-based Design of Experiments- Process perturbation, to see how the process is affected by potential issues or changes- Conversion from batch to continuous- Modelling of process- Integration of process control to measure and analysis the process