Jan Baptita Van Helmont discovered in the 17th century that rotting organic materials may produce combustible fumes. The first digestion facility was erected in Bombay, India, in 1859, and by 1895, anaerobic digestion was being utilized to recover gas from waste management in England. In America, Henry Ford is often credited with introducing the anaerobic digester as part of his vision for a clean environment.
Anaerobic digestion is the process of decomposing organic material in the absence of oxygen. Organic material is any substance derived from biological sources such as plants or animals. It can be burned as fuel or disposed of in an environmentally friendly way. Waste products from human activities contain large amounts of potential anaerobic digestion material, including food waste, sugarcane bagasse, dairy manure, sewage sludge, and many types of industrial by-products. Anaerobic digestion has been used for centuries in parts of Europe and Asia to generate energy from food waste and other agricultural residues. Modern technology has improved the efficiency of anaerobic digesters and reduced the cost of treatment. The resulting biogas can be used directly as fuel, or it can be further processed to yield liquid fuels (such as methanol) and other useful products.
People have been using anaerobic digestion to dispose of household waste since at least 1880, when Ford introduced his model T truck.
More recently, the twentieth century saw a revival of both industrial and small-scale biogas systems. The Flemish scientist Jan Baptise van Helmont discovered in the 18th century that decaying organic materials created a flammable gas. He called this gas methane.
Biomethanation is the process by which bacteria or other organisms convert biomass into biofuel or biogas. Biomethanation can be divided into two main processes: anaerobic digestion and aerobic degradation. Anaerobic digestion does not require oxygen and is commonly used to produce renewable energy from food waste, manure, sewage, agricultural residues, and many other types of organic material.
Aerobic degradation uses oxygen and is usually applied to paper, yard waste, wood, plastic, and other organic materials that cannot be treated with anaerobic digestion.
The first patent for producing biogas was filed by Charles Hall in England in 1872. He called his invention a "gas engine". A German inventor named Carl von Linde took out another patent on such a device one year later.
The first commercial biogas plant in the United States started up in 1978 in Salem, Massachusetts. It converted kitchen grease and animal fat from a local slaughterhouse into energy for electricity and heat. As of 2015, there are approximately 150 biogas facilities operating in 20 countries on five continents.
Biogas is thought to have been used for heating bath water as early as 10 B.C. Anaerobic digesters can eliminate more than 90% of disease-causing bacteria that would otherwise reach surface waterways and jeopardize human and animal health.
The first anaerobic digester was built in 1953 at Woburn Abbey, England. It was designed by R. M. Smeeton from the Department of Agricultural Engineering at Cambridge University.
The goal was to find a way to make liquid manure safe to spread on land without contaminating it with pathogens that could cause disease. In addition, there was a need for an alternative source of energy for farmers who were removing horses from roadways.
Anaerobic digestion is the process of transforming organic material into methane and carbon dioxide under anaerobic conditions (without oxygen). The term "biomass" refers to all plant and animal matter not made up of pure carbon or hydrogen (i.e., biomass contains oxygen), while "fossil fuel" refers to material derived from ancient plants and animals that still contain large amounts of energy. Biomass can be burned in a reactor to produce heat and electricity, but its main use is for producing gas. There are two types of anaerobic digestion processes: thermophilic and mesophilic.
As gas became the dominant heat source, ovens got smaller and lighter. In 1826, James Sharp, a British inventor, invented the gas stove. By the 1920s, most residential kitchens had gas ovens. During this time, electric appliances were becoming available, but they were too heavy for use in the home kitchen.
The first gas-electric combination refrigerator/freezer was developed by Harvey Hubbell and introduced by General Electric in 1943. This revolutionary new appliance combined the efficient cooling of an ice cream freezer with the ease of operating a gas range. It changed the way families cooked and ate.
Gas is made up of many small molecules called gases. These gases can be burned in a flame to produce heat. When burned, they create carbon dioxide and water vapor as products. The two main types of gas used in homes are natural gas and propane gas. Other gases such as oxygen, nitrogen, and argon are also used in small quantities for specific applications.
Natural gas is the cleanest burning of all the fossil fuels. It does not lead to as much air pollution as oil or coal and it produces less carbon dioxide than either oil or coal. Natural gas is found under ground in large reservoirs. Before it can be used, the gas must be extracted from the ground. This process requires drilling wells into the reservoir and using pumps to extract the gas.
The specific beginnings of cooking are unknown, but early humans conquered fire and began using it to prepare food at some time in the distant past. Researchers have discovered what appear to be the remains of campfires built by Homo erectus, an early human species, 1.5 million years ago. These fires were probably used to roast meat.
The first known written recipe comes from Mesopotamia and dates back about 5,000 years. It was written on a clay tablet issued by the ruler of Ur who asked for good wine to be brought to him so that he could eat with his friends.
Ur was a city-state in present-day Iraq who's territory extended into what is now Lebanon. It was one of the most advanced civilizations in the world with a rich culture that included writing, mathematics, science, medicine, religion, and food preparation.
In addition to the written recipe, the king's messengers also brought along animals (mainly sheep and goats) that had been killed by hunters and butchers and placed before their lord for consumption. This shows that in ancient times food wasn't always available around the clock like it is today. People had to go out and hunt or grow their own food which explains why many recipes include instructions for making use of leftovers.
People usually ate three meals a day, although in times of war or poverty this amount might be reduced to two meals or even one.