CO2-Binding of ammonoxidized lignins and their use as soil improvers (COBAL)

木质素和其他木质生物材料可以通过氧化氨解（氨氧化）转化为人工腐殖质物质。该反应利用氧气和氨水分解芳香木质素部分，并以氨盐、尿素、酰胺和胺的形式引入氮。得到的“n -木质素”是一种有机无机肥料，可用于退化土壤的修复。n -木质素的一个特殊价值是缓慢的氮释放效应，这是由氨氧化产生的不同氮结合形式的不同水解速率引起的。仲胺能够以2:1的配合物形式结合二氧化碳，这种配合物既可以被描述为加成产物，也可以被描述为离子对（二烷基氨基甲酸二酯，二烷基氨基甲酸二酯）。这种化学行为被应用于当前的项目中，使用n -木质素作为二氧化碳固定的手段。采用（二）甲胺代替氨氧化，可进一步提高n -木质素中作为co2结合位点的仲胺和酰胺的含量。氨氧化木质素的co2结合（简称“COBAL”）是本项目的关键问题。这包括对中间体和产品的潜在化学和综合分析表征的研究，包括同位素标记（15N, 13C）和液体和固体状态的核磁共振波谱作为主要的方法方法，以及对土壤修复，农业和园艺产品的测试。该工艺的优点是同时将两种散装“副产品”（CO2和木质素）转化为具有高实用价值的增值产品（具有腐殖质特性的有机矿物肥料），并返回到自然循环中，基于木质素和CO2的散装可用性的大规模适用性，对高级土壤改良材料的高需求，以对抗日益严重的全球荒漠化，以及产品的环境兼容性。

Lignin and other ligneous biomaterials can be converted into artificial humic substances by oxidative ammonolysis (ammoxidation). This reaction employs oxygen and aqueous ammonia to break aromatic lignin moieties and to introduce nitrogen in the form of ammonia salts, urea, amides, and amines. The resulting “N-lignin” is an organo-mineral fertilizer which can be used for rehabilitation of degraded soils. One special value of N-lignins is the slow-nitrogen releasing effect, which is caused by the different hydrolysis rates of the different nitrogen binding forms generated upon ammoxidation. Secondary amines are able to bind carbon dioxide in the form of 2:1 complexes which can be described both as addition products and as ion pairs (dialkylammonium dialkylcarbamates, dialcabs). This chemical behaviour is applied in the current project to use N-lignins as a means of CO2 fixation. Employing (di)methylamine instead of ammonia in the ammonoxidation, the content of secondary amines and amides as CO2-binding sites in N-lignin can be additionally increased. CO2-Binding of Ammoxidized Lignins - abbreviated “COBAL” as short term - is the key issue of the present project. This comprises studies as to the underlying chemistry and comprehensive analytical characterization of intermediates and products, involving isotopic labelling (15N, 13C) and NMR spectroscopy in liquid and solid state as the main methodic approaches, and the testing of the products in soil rehabilitation, agriculture and horticulture. The advantages of the process are the simultaneous conversion of two bulk “by-products” (CO2 and lignin) into a value-added product of high practical relevance (organo-mineral fertilizer which humic properties) that is returned into the natural cycle, the large-scale applicability based on the bulk availability of lignin and CO2, the high demand for high-grade soil improving materials to combat the progressive global desertification, and the products´ environmental compatibility.