Method for producing biogas through coupling biodiesel oil byproduct crude glycerine purification and pretreated agriculture and forestry residue fermentation

Abstract

The invention provides a method for producing biogas through coupling biodiesel oil byproduct crude glycerine purification and pretreated agriculture and forestry residue fermentation. The method comprises the following steps: adding a methanol solution of phosphoric acid into biodiesel oil byproduct crude glycerine, meanwhile, adding agriculture and forestry residues, carrying out uniform stirring so as to obtain a crude glycerine solution, subjecting the crude glycerine solution to standing, carrying out filter pressing so as to separate out a solid phase, i.e., treated agriculture and forestry residues and a liquid phase, subjecting the treated agriculture and forestry residues to anaerobic fermentation to produce the biogas, subjecting the liquid phase to standing layering so as to obtain an upper layer, i.e., a methanol phase and a lower layer, i.e., a glycerine phase, recycling methanol, neutralizing glycerine until the glycerine is neutral, adsorbing the neutral glycerine solution with activated charcoal, then, filtering the glycerine solution, and subjecting the filtered filter liquor to ion exchange and concentration, thereby obtaining purified glycerine. According to themethod, biodiesel oil crude glycerine purification and agriculture and forestry residue pretreatment are treated in a cooperated manner, available ingredients are effectively recovered from the biodiesel oil byproduct crude glycerine, and thus, the recoverable utilization of resources is achieved, so that the method has good economic and environmental benefits.

Description

Technical field: [0001] The invention belongs to the technical field of biomass purification and pretreatment methods, and in particular relates to a method for biodiesel by-product crude glycerol purification coupled with pretreatment for fermentation of agricultural and forestry residues to produce biogas. Background technique: [0002] Glycerin is widely used in medicine, food and tobacco because of its high viscosity, strong hygroscopicity, high boiling point, water solubility, non-toxicity, low freezing point, good water holding capacity, easy decomposition by microorganisms, and three hydroxyl groups that can be made into some derivatives. It is an important light chemical raw material for more than 1,700 products in industries such as cosmetics, ink, national defense, leather, printing and dyeing, paint, synthetic resin, pesticide, toothpaste, and microbial fermentation. [0003] In my country, almost all high-purity medical glycerin (more than 99.5%) relies on import...

AI Technical Summary

Problems solved by technology

The source of raw materials is complex, and its by-product crude glycerin generally has poor quality, low purity, many impurities, complicated processing, and production problems

It can be seen that the simple separation technology commonly used by domestic biodiesel enterprises to process crude glycerin leads to low recovery and purity of glycerin, which cannot produce high economic benefits for enterprises