Naturally, efficiency and high reliability are most important requirements when it comes to an economic and competitive production. But the idea of sustainability becomes more and more important to companies when it comes to weigh the pros and cons of a capital investment. The innovative ASCO CO2 stack gas recovery plant incl. ASCOSORB technology scores with an environmentally friendly overall concept for CO2 recovery. The modern system allows the HOCHDORF Swiss Nutrition AG to recycle more than 90 percent of the CO2 contained in the plant´s stack gas. Dr. Karl Gschwend, Managing Director Strategic Projects, explains, “As one of the Swiss market leaders in the development, manufacture and marketing of valuable food, environmental protection has always been a major concern to us. The new ASCO recovery plant provides the optimal solution to produce sustainable and to be able to reduce CO2 emissions by up to 10-15 percent each year. So CO2 exhaust gases can be prevented and used profitably for our company."
Caption: ASCO engineers ensure a smooth operation of the modern CO2 stack gas recovery plant through regular maintenance.
In the first process step, the flue stream from the client´s steam boiler is collected, cooled and treated in the scrubber to remove any solids and sulfur compounds present. Subsequently, the CO2 is selectively absorbed from the flue stream by means of a special solution in order to get liberated later in the process with the help of thermal energy, providing CO2 gas for further processing. In the following steps, the gas is compressed, further purified, dried and liquefied so that it can be stored in tanks. The balance of the flue stream – mainly water vapour, nitrogen and oxygen – is vented to the atmosphere. The plant´s capacity of 285 kg/h allows to recover up to 2,200 tons of CO2 profitably and environmentally friendly each year.
Caption: The shown process unit consists of various pumps and heat exchangers and is responsible for heating or cooling of the CO2 gas and the wash solution.
Marco Pellegrino, Managing Director ASCO CARBON DIOXIDE LTD, takes a stand on the quality of the recovered CO2, "There is a zero tolerance policy when it comes to CO2 purity and therefore to the hygiene requirements for food, particularly baby food. In our case, the recovered carbon dioxide meets the specifications of ISBT and the requirements of other food and beverage standards in its entirety. In addition, our CO2 stack gas recovery system offers a profitable source of CO2 for the HOCHDORF Swiss Nutrition AG as well as a cost-effective alternative to conventional CO2 production or purchase of liquid CO2."
The new facility is equipped with the so-called ASCOSORB technology which Pellegrino characterises as follows, "Thanks to this revolutionary technology huge energy savings and thereby greatly reduced operating costs are guaranteed. The energy usage is just 0.9 MWth / 1000 kg of produced CO2. The specially formulated ASCOSORB solvent is largely resistant to oxygen which typically results from stack gas sources allowing greater system efficiency and longevity of the plant. In addition, further costs can be reduced thanks to a significantly lower consumption of absorbents. Modern CO2 stack gas recovery technologies such as our ASCOSORB technology would be able to prepare million tons of environmental toxins every day and consequently reuse the gas instead of expel it into the atmosphere – a technological and environmental milestone," Pellegrino adds.
Caption: The CO2 compressor compacts the CO2 gas to a pressure of 16 to 20 bar.
Most part of the gas is recycled to the production plant of the Swiss food manufacturer. Among other things, it is used for inerting packaged milk powder. The advantage of inerting with CO2 gas is the elimination of oxygen which prevents sensitive products such as baby food powders from oxidation and the formation of unappetising odours.
Caption: Process unit with heat exchangers and pumps in the front, absorber and desorption columns in the background.
For a successful implementation of this project, HOCHDORF Swiss Nutrition AG closely cooperates with Messer Schweiz AG which is owner of the new ASCO CO2 stack gas recovery plant. Messer Schweiz AG acquired the facility from its subsidiary ASCO CARBON DIOXIDE LTD last year. The premises and the combustion processes of HOCHDORF Nutrition AG are used for the accommodation of the plant system and as CO2 source for the recovery process. That high-quality CO2 which doesn´t flow back in the production plant of HOCHDORF Swiss Nutrition AG is sold to end customers by Messer Schweiz.
The ASCO recovery plant was put into operation in August this year and is running to the full satisfaction of the customer since then.
About HOCHDORF Swiss Nutrition
The HOCHDORF Group is active in the areas of dairy ingredients, baby care and cereals & ingredients and has a staff of around 570 employees. The products are sold worldwide in over 80 countries. Customers include the food industry and the retail sector. The factory in Sulgen is competence center for milk and whey powder as well as infant foods and processes 230 million liters of milk and 60 000 tonnes of whey every year. www.hochdorf.com
About Messer Schweiz
Messer Schweiz AG is one of the leading industrial gas companies in Switzerland and provides gases for industrial, medical, pharmaceutical and food to companies in Switzerland, hospitals and research institutes for more than 100 year now. Included are gases like oxygen, nitrogen, argon, carbon dioxide, hydrogen, helium and gas mixtures. The company employs over 100 people and is part of Messer Group GmbH, the world's largest owner-managed industrial gas company. www.messer.ch